CITY ROADS 



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PAVEMENTS 



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Book_ Ig'^^ 

Copyright N" 

COPVRIGHT DEPOSIT 



CITY 



Roads and Pavements 



SUITED TO 



CITIES OF MODERATE SIZE 



Second Edition, Revised and Enlarged, 



BY 



William Pierson Judson, 

M. Am. hoc. Municipal Improvements, 

M. Am. Soc. C. E., 

M. Inst. C. E. 



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NEW YORK 

The Engineering News Publishing Co. 

1902. 



THE LIBRARY OF 
CONGRESS, 

Two Copies Received 

JUL. 26 1902 

Copyright entry 

01 ASS VtXXa No. 

COPY 8. 



Copyright, 1902 

by 

WM. PIERSOX JUDSON. 



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CHAS. VAN BENTHUYSEN & SONS, 
PRINTERS. 



TABLE OF CONTENTS. 



PREPARATION OF STRP:ETS FOR PAVEMENTS— (Page 7) 
Reduction of width. Drainage. Subdrainage. Rollers. Roll- 
ing dirt roads. Wide tires. Pressure of traffic and of struc- 
tures. 

ANCIENT PAVEMENTS— (Page 17) 

Oomparisons. Stone wheel-tracks ; competition with first 
railway. 

MODERN PAVEMENTS— (Page 25) 

Comparative loads. Cost. Pavements for steep grades : 
asphalt; vitrified brick; creosoted wood block; block stone; 
broken stone ; bituminous macadam, Crown of pavements : 
Rosewater formulas of 1898 and 1902. Form of crown: for 
macadam. Falls of horses on different pavements. Culverts: 
kinds ; sizes ; costs. Curbs : kinds ; sizes ; costs. Car-track 
construction. 

CONCRETE BASE FOR PAVEMENT— (Page 42) 

Need. Subgrade. Cement : simple outfit for easy tests ; fine- 
ness ; quickness; soundness; purity ; weight ; results. Manner 
of use. Aggregates. Sand. Proportions and mixing. Water. 
Machine-mixing. Spreading and ramming. Monolith. Sur 
face. Setting. Wetting. Freezing : use of brine; limit of cold 
Cost, Portland. Natural. Extra work. Table, 36 cities. 

BLOCK-STONE PAVllM HNTS— (Page 57) 
Defects. Merits. C'ost. Extent. 

WOOD PAVEMENTS— (Page 66) 

Old. Cedar block. Modern. Australian. American • kreo- 
done-creosote; creo-resinate ; cost. 



TABLE OF CONTENTS. 

VITRIFIED BRICK PAVEMENTS— (Page 82) 

Modes. Extent. Objections. Production. Characteristics. 
Qualities. Tests. Examination in use. Construction : base ; 
sand cushion ; joint-fillers ; expansion. On steep grades. Cost. 
Guarantee. 

AMERICAN SHEET-ASPHALT, ARTIFICIAL AND NA, 
TURAL— (Page 103) 
Comparison. History. Artificial. Natural. Companies. 
Sources. American artificial : materials and methods ; founda- 
tion; binder ; wearing surface ; roUing. Steep grades. Crown. 
Railway tracks. Cost. Guarantee. Causes of failures. Block- 
asphalt; extent; cost. Comparative preferences, asphalt and 
brick. 

BITUMINOUS MACADAM PAVEMENT— (Page 131) 
Characteristics. Details. Methods Cost. Opinions. 

BROKEN STONE ROADS— (Page 138) 

Extent. Rock for roads. Tests of rock. Telford and Mac- 
adam : relative costs. Binder : mode of use ; (quality ; quan- 
tity. Maximum grades. Construction. Subgrades of various 
kinds. Rock : crushing ; screening. Base. Top. Thickness. 
Crown. Cost. Cautions. Maintenance. Methods of repairs • 
raveling ; rolling ; ruts ; cleaning ; cost. Re-surfacing : methods ; 
cost, 

INDEX— (Page 187) 



PREFACE TO SECOND EDITION, 



The local features of the fir.^t edition, havini^ served their purpose, 
have been omitted, and modifications have been made to show the 
present applications of general methods, some of which have 
changed since 1894. The most marked change during the past eight 
years has been in the increased use of crushed stone for roadways of 
macadam and of telford construction, on the improved streets of 
villages and cities. A notable instance is that of the city of Greater 
New York, which contains outside its parks eight hundred miles of 
crushed stone roads built since 1894. 

This general increase has resulted in part from the work begun in 
1893 by the State of New Jersey, followed in 1894 by Massachu- 
setts, in 1895 by Connecticut and in 1S98 by New York. The 
examples given by the governments of these States in building 
highways by State aid and outside corporate limits, have led to 
the building by the municipalities of similar roads within many cities 
and villages, which have thus wisely profited by the experienced 
methods of State officials. 

The results have l)een an increasing extent of the best kinds of 
roads of broken stone, and a growing knowledge of the methods 
and machines by which alone can such roads be built and main- 
tained. These are here described under the heading " Broken 
Stone Roads," without however differing essentially from the 
descriptions given in the first edition. 

The grade of a city street is usually a fixed condition and not a 
theory, and it is often difficult to decide which is the best pavement 
for a fixed steep grade in a given climate, or how steep a grade will 
give good results with a given pavement. Tables of actual instances 
are given in order that engineers may know where to find condi- 



PREFACE TO SECOND EDITION. 

tions similar to their own, and where they may examine certain 
pavements in actual use. To watch the traffic using a steep paved 
slope or to examine its condition during a sharp shower or after a 
heavy rain, will suggest points as to the proper grade and crown 
which will be worth any amount of theorizing as to maximum 
grades. 

The sections entitled respectively " Concrete Base," '^ Block 
Stone," " Wood," " Vitrified Brick,' " Asphalt," " Bituminous mac- 
adam '" and " Broken Stone," are made to accord with the latest 
records of methods and costs, using illustrations and tables for 
brevity. These records have been obtained from personal practice 
and investigation and from the publications and discussions of the 
several Societies of Civil Engineers, from the reports of the officials 
of States and Cities, and from the columns of Engineering News, 
The Engineering Record, Municipal Journal and Engineer, The 
Engineering Magazine and Municipal Engineering, and also directly 
from many civil engineers in addition to those whose names are 
mentioned. The uniform courtesy shown by civil engineers, both 
in the United States and abroad, in cordially meeting inquiries 
regarding their works, methods and results, and in freely giving all 
desired information, is a marked and peculiar characteristic of the 
Profession. 

These statements of facts and opinions are meant for those who 
wish to profit by the varied experiences of practical road makers. 

Wm. p. J. 
Oswego, New York, 

May I, 1902. 



CITY ROADS AND PAVEMENTS 

SUITED TO CITIES OF MODERATE SIZE. 



The extent of street-surface in the cities having a 
population of fifty thousand or less is usually such that 
only a portion can be paved or improved at any one 
time, and it is therefore necessary to carefully study 
the local conditions existing in any given city in order 
to determine which of the various kinds of pavement 
are best suited to the existing conditions of slope and 
of trafific and of treasury, and to the local supplies of 
proper materials. 

REDUCTION OF SURFACE TO BE PAVED. 

In cities which have always had dirt roads, the actual 
width of roadway is usually much greater than is 
needed for the traffic, and the subject should first be 
studied with a view to reducing the area to be paved 
by widening the bermes and the sidewalks on each side 
of the street, and thus narrowing the roadway to a 
width no greater than the traffic demands. Many 
cities have 42 feet to 45 feet width of dirt roadway on 
residence streets where 26 feet and 32 feet would be an 
ample width between the curbs of the same streets 



CITY ROADS AND PAVEMENTS. 

when they are paved ; 32 feet is the width most often 
used. The beauty of the streets will be much improved 
by such change and by forming on each side of the 
street a w^ider grassy berme outside of a row of trees, 
and this change will also give room for wider sidewalks, 
which in many cases are much needed. These wider 
bermes can usually be formed from the worn earth 
and sand which must be scraped from the surface of the 
existing old roadways before attempting to form new 
ones. 

DRAINAGE OF ROADWAY. 

Having determined the proper widths of roadway of 
the various streets, their grades should be most closely 
studied in order to get the best results with the least 
change of existing grades ; it should be considered that 
the proposed pavements with their curbs, crossings, 
manholes and catch-basins will be, or should be, per- 
manent structures and they should be located carefully. 

Before paving any street, there should be in place a 
complete system of sewers and of pipes for water and 
for gas with service-branches to every lot on both sides 
of the street, and with manholes to give access to the 
sewers, and with catch-basins so arranged as to take 
the storm-waters without blocking the sewers with 
street-waste and silt, which can readily be prevented 
from entering the sewers by the use of recent improve- 
ments in catch-basins. In designing these sewers, and 
in considering whether existing sewers are sufficient, it 
must be remembered that the proposed pavements will 
bring the storm-water into the sewers more quickly and 
that larger capacity will be needed to carry the in- 
creased flow. 

8 



SUB-DRAINS. 

Careful consideration sliould also be u"i\'en in order 
to decide whether the local conditions make it best to 
pro\'ide sub\va)'s for electric wires. 

The thorough drainage of such streets as ha\e been 
naturally muddy in spring and in fall, must be provided 
for before any method of pa\'ing or surfacing is consid- 
ered. The natural earth is the real roadbed which 
does the work, and it can only support the pave- 
ment — of whatsoever kind it may be — by being- 
kept dry. 

In most of the cities, a portion of the streets have 
good grades and will drain naturally if rightly formed ; 
and it is the streets running at right angles to these 
which will be most difficult to drain, especially if thev 
are on a hillside ha^ing springs in the subsoil, which 
must then have sub-drainage by tile drains before an\' 
form of surface or of pavement will be of permanent 
value or effect. 

There are many such streets on which rain water 
now stands until it evaporates. On the ordinary street 
in northern cities, the direct rainfall between fence- 
lines per mile, is equal to 30,000 tons or 8 million 
gallons of water every year, and there are mam' streets 
where this water has been left to evaporate or to soak 
into the ground. 

SUB-DRAINS. 

Any such roadbed, where, from any cause, water 
naturally stands and forms mud, must be thoroughly 
sub-drained. To put broken stone, or gravel, or anv 
valuable material of any kind upon a bed of earth and 
ashes which rain will conxert to mud, is to throw away 
both money and material. 



CITY ROADS AND PAVEMENTS. 

The sub-drains should consist of Hnes of two inch 
to four inch porous tile, or four inch to six inch vitri- 




fied tile laid with open joints ; one line on each side 
of a level road which receives drainage from both sides, 
or one line only on a hill-side road, this being put 




on its up-hill side to intercept ground-water from the 
higher ground. These tiles should be placed on an 
accurate grade, a foot or more below the bottom of the 
gutter, next to the curbs, away from tree-roots and 
below frost, in order to lead the ground-water to the 
catch-basins or road-culverts, from which it will run to 
the sewers or outlets with the surface-water from the 
pavement. 

The provision of this sub-drainage should be the 
first move toward making any permanent roadway on 
a fiat street. 



ROLLING THE EARTH ROADBED. 

For any method of road-making or of paving which 
may be adopted, a steam roller of about ten to twelve 

lO 



ROLI.INCr THK KARTII K( )AI)l',i;i ). 

tons weight is requisite in order to compact the eartli 
roadbed so that it will sustain the wheels which will 
pass over it. As well try to make the bricks of old 
Egypt without straw as to try to make the roads of 
to-day without a heavy steam roller. Every fully 
equipped road-builder has one or more. There are few 
cities which have not made some effective efforts to 
have good roads, and those which have done so know 
from experience that no good results can be expected 
until the proper tools are used. For any system of 
pavements or of roads, a steam roller is the thing first 
needed, and no contractor's bid should be considered 
unless he agrees to provide and use a steam roller of 
at least ten tons weight so proportioned as to give not 
less than 500 pounds pressure per lineal inch of face of 
the roller-wheels. 




The undulations and hollows which may be seen in 
the surface of many existing pavements are the direct 
results of the lack of a proper roller which would first 



1 1 



CITY ROADS AND PAVEMENTS. 

have disclosed the presence of the soft places in the 
earth roadbed, and then would have packed the grad- 
ing-material into them, so that the finished pavement 
would have had a solid and peniianent foundation and 
a regular surface. 



GOOD EFFECT OF ROLLER OX DIRT ROADS. 

Especially valuable would such a roller be for cities 
ha\dng great extent of dirt roads, which could be fonned 
by use of the wheeled scraper and then rolled to a 
smooth, hard surface, furnishing fine roadwavs during 
the summer months until the fall rains make them 
muddy. By rolling the roads as thev freeze, towns can 
make their earth streets smooth for the whole ^\"inter 
and so that a few inches of snow will give good 
sleighing. 

Nearly a mile per day of temporary, summer road- 
wav can be made at small cost by a scraper, sprinkler, 
and steam roller working together. 

The sprinkler should be selected to have six-inch 
tires with rear axle two inches longer on each end than 
the front axle ; it should be built without a reach so 
that it can be turned without digging holes in the 
roadv\'ay, and should have a sprinkler which is under 
the perfect control of the driver. 

The roller should be selected to be of not more than 
ten or twelve tons actual weight when loaded, so that 
it can cross ordinaiy bridges safely and can roll streets 
^rithout crushing buried pipes. The roller should be 
tested to see that it can climb ten per cent grades when 
thev are covered with loose stone, and also that it can 
hold its steam-pressure during continuous operation, 



12 



PRKSSIKK OF 'IKAKFK 



and it should also have a record for durability under 



rough usage. 



WIDE TiRKs ON \viii:i:i.s. 

To supplement the good effect of a roller on the dirt 
roads, which are now cut by narrow tires, the use of 
wide tires on heavy wagons should be required. The 
following is a practicable way of initiating such a rule: 

Let the Board of Public Works of any city order that 
no wagon will be employed upon city work unless it 
has four-inch tires on its wheels, with the front axle 
eight inches shorter than the rear axle. This will 
make each wagon equal to two eight-inch rollers. 

Let the same order be applied to ice- wagons and to 
public carters, as a condition of issuing a license. A 
future date could be published at which all heavy 
wagons doing business in the cit)', including farmers' 
wagons from the surrounding country, shall have such 
wheels. This publication will stop the sale of narrow- 
tired wagons, which will gradually be displaced by 
those with wide tires, when the roadways of the vicinity 
as well as of the city itself, will no longer be so deeply 
cut and furrowed as now by the pressure of traffic. 

PRESSURE OF TRAFFIC. 

It is only necessary to consider the great pressure 
which ordinary traffic will put upon the roadbed in 
order to realize that no pavement can keep its form 
and its regular surface unless the earth roadbed, on 
wliich all the pressure finally comes, has been perfectly 
compacted before the pavenient is laid over it; for the 
pavement, of whatex'er material it may be, is merelv a 

13 



CITV ROADS AND PAVEMENTS. 




14 



COMPARISON WITH PRESSURE OF STRUCTURES. 

more or less rigid surface wliicli receives tlie pressure 
of traflfic and distributes it to tlie supporting eartli. 
For instance, the ordinary coal wagon, weighing 1,200 
pounds, draws two tons of coal and has tires two inches 
wide. As the wagon stands on the pax'enu'nt, thu 
bearin«^ surface does not exceed a leuLTlh of one and 
one-half inches on each wheel; the four wheels thus 
standing upon a total surface of twcK^e squai-e inches, 
with a total pressure of 5,200 pounds, or 433 pounds per 
square inch, and this is applied with a rolling pressure 
w^hich is most destructive. 

COMPARISON WITH PRESSURE OF STRUCTURES. 

The degree of pressure which this puts upon any 
pavement will be best appreciated bv comparing it with 
the pressures per square inch upon the clay, sand, or 
earth underlying the foundations of some well-known 
great structures. 

The Cleveland viaduct 14 to 23 lbs. per sq. in. 

The 1 894 London tower bridge 21 " " 

The sixteen-story office buildings of Chicago 21 " " 

The Memphis bridge piers ... 22 " " 

The Albany capitol 28 " 

The Brooklyn bridge anchorage 56 " " 

The earth supporting these structures is, of course, 
compressed to the greatest degree in its natural forma- 
tion, but the average pressure of these structures is less 
than one-sixteenth of the pressure concentrated on an 
ordinary wagon wheel. 



15 



CITY ROADS AND PAVEMENTS. 




Ancient Roman Road, 




Early Eighteenth Century Road. 




Late Eighteenth Century Road. 




Modern Macadam Road. 



RELATIVE THICKNESS OF ANCIENT AND MODERN ROADS. 

I6 



ANCIENT PAVEMENTS. 



Paved highways were built by the Romans througli 
Europe and throughout tlie Empire two thousand to 
twenty-two hundred years ago, and portions of these 
pavements still endure. Many of them have been 
examined to learn whether the details of their con- 
struction included features which are now worth}' of 
imitation. 

It is found that the locations of these roads were 
usually made in the simplest manner, ignoring natural 
obstacles and directing the course by straight lines 
toward prominent landmarks. Upon the lines thus 
defined, the width of the proposed roadway was then 
marked by two parallel furrows which were eight feet 
to twenty feet apart according to the importance of the 
highway. Between these furrows all unstable materials 
were excavated, usually to a depth of about three feet, 
and in this undrained trench the road materials were 
placed in more or less regular layers. 

The statitnicn, or base, was formed of one course, or 
sometimes of two courses, of large flat stones laid in 
lime mortar, and was usually about fifteen inches thick. 
Upon this was formed a 9-inch course of small frag- 
ments of stone which were embedded in sufficient lime- 
mortar to fill their voids, and which thus bound 
together the tops of the large stones of the stahcincn : 



17 



CITY ROADS AND PAVEMENTS. 

upon this, the nucleus was formed of fragments of 
gravel, stone, pottery and brick mixed with Hme-mor- 
tar to form a concrete, which was consoHdated by ram- 
ming, and was made about six inches thick. Upon 
this the sum7na crusta (top crust) or pavimeut win (hard 
surface) was formed of closely-jointed, irregular stones, 
which formed a mosaic about six inches thick, the top 
of which was practically on a level with the adjoining 
natural surface of the ground. 

In and near the cities \\\^ pavimentiim was formed 
of larger irregular blocks of basalt, or porphyry or lava, 
two to two and one-half feet in length and width and 
twelve inches to fifteen inches in thickness, which were 
dressed and fitted together with extreme accuracy and 
were bedded in cement. 

In a general way there were thus used various ma- 
terials and varied methods, none of which showed any 
attempt at drainage of the subgrade, and all of which 
were wasteful of the materials and labor, which then 
cost nothing but the lives of captives, who were forced 
to build these highways for the armies of their 
conquerors. 

The results were roads which were remarkable for 
their strength and durability and for little else. If 
anyone were so unwise as to attempt to build similar 
roads now, the cost would be from four to eight times 
the present cost of our most expensive modern pave- 
ments which are, in every way, better for modern uses, 
and upon which the cities of the United States are 
estimated to have expended half a billion of dollars. 

STONE WHEEL-TRACKS. 

This peculiar form of stone pavement has long been 
in use in the midst of the roughly paved streets of 

i8 



STONK \viii:kl-tracks. 

many Italian cities and towns, and in sonic of tlic 
largest Scotch and English cities, which facts probably 
susr^ested its use on the Albany and Schenectady turn- 
pike in 1833, \yhen \yheel-tracks, which are still in use, 
and which are here shown by a photograph taken in 
1 90 1, were built on two miles of the worst parts of this 
main highway to the West, and which Vv'ere later 
made to coyer the dry and sandy parts of the fourteen 
miles between the two cities. 

There are, in 1902, no memories among the oldest 
residents along the road and no published accounts in 
local histories, of the origin and details of this interest- 
ing pavement, and those which are here given were 
only found by search amidst a mass of old letters and 
papers which were saved from an abandoned gate- 
house by Wheeler B. Melius Esq. of the Albany His- 
torical Society. 

The turnpike itself was opened to travel in 1805, be- 
ing made twelve feet wide of gra\'el at a cost of $8,400 
per mile. After ten years of attempts to maintain this 
gravel road under the traffic of many heavy narrow- 
tired wagons drawn by four or six horses, a "sunken 
pavement " of cobbles was built on the dry and sandy 
parts of the road, and broken quarry stone to the depth 
of twelve inches, was "bedded" on the wet and clayey 
parts, the edges being "bonded" by lines fifteen to 
sixteen feet apart, of small boulders twelve inches to 
twenty-four inches in diameter embedded in the earth 
along each side. Under date of January 8, 183 1, the 
President and Directors of the Turnpike Company 
reported to the Legislature that they had "hitherto 
been unable to render said road hard and solid and to 
keep the hard materials (grax'el, broken (|uarrv-stone 

19 



CITY ROADS AND PAVEMENTS. 

and cobbles) on the surface of the earth." In April, 
1 83 1, strenuous protests were made by the stockholders 
of this Turnpike Company, Chancellor Kent among 
others, against the effect of the charter granted in 1826 
to the Mohawk and Hudson Railroad Company, on the 
ground that 

" Should the Rail Road Company succeed, their operations will 
necessarily diminish materially the tolls of the Turnpike Company, 
and thus sap the consideration upon the faith of which the latter 
have constructed their road." 

Referring to the application of the Railroad Com- 
pany for leave to run a side-track into the heart of 
Albany, Chancellor Kent wrote from New York under 
date of April 7, 183 1 : 

"If that would not be an interference with the rights of the 
Turnpike Company, then nothing would be an interference short of 
plowing up the Turnpike Road." 

It was feared that the Railroad might eventually dis- 
place the stages, the tolls from which formed a large 
portion of the revenues of the previously-chartered 
Turnpike Company, then amounting to $5,137 per 
annum ; one-third of which was paid out to gate- 
keepers and overseers and the balance was expended 
in repairs and occasional small dividends: the tolls 
were levied on a peculiar system by which a four-horse 
stage paid 43/4 cents to enter upon the road at either 
end and the same amount to leave it, or 87 cents for 
each single trip. 

The steam railroad was, however, built, and was 
opened to operation on September 12, 183 1, as the first 
exclusively passenger railroad in the world. The 
handling of freight by the railroad was not begun till De- 



20 



STONK WI I KKl. -TRACKS. 

cember 6, 1832, as detailed in a letter from the manager 
to the president, when three cords of wood, making 
two car-loads, were taken to Albany, and were the first 
freight carried on what is now the New York Central 
Railroad. In order to compete with the railroad, the 
Turnpike Company then made many efforts to arrange 
to build another railroad of their own along the side of 
the turnpike,* and the failure of these efforts resulted 
in deciding, in 1832, to lay the "stone rails," of which 
twenty thousand linear feet were brought from Whalen's 
limestone quarries at Flint Hill, eight miles up the 
Mohawk valley from Schenectady, and were laid in 
1833 and 1834, and extended later. Sections of this 
stone wheel-track, in some cases half a mile or more in 
length, are still in good condition and in daily use, as 
shown in the photograph made in 1901. 

The " stone rails " were made four inches thick and 
were roughly cut eighteen inches to twenty-four inches 
wide, of any length from two to eight feet, with square 
ends to be laid close together and with both faces flat 
to permit of turning over when w^orn. The slabs now 
show a concave surface worn one to two inches at the 
center. They were bedded in the gravel and broken 
stone of the roadway, by two men at the rate of 1 25 feet 
per day or one and one-half cents per running foot, the 
cost of the stone delivered ready to lay being thirteen 
cents per running foot. This made the wheel tracks 
cost $1,530 per mile while the cobble paving two feet 
to three feet wide between the tracks and five feet wide 
on each side of the tracks cost $1,610 per mile: Form- 
ing the roadbed cost $160 per mile, or a total of $3,300 
per mile completed. A few slabs which have Ix'en 

* Finally accomplished, in 1901-2 by buildintra double track electric road. 

21 



CITY ROADS AND PAVEMENTS. 




5 ft. of large cobble pavement. <^ 



6 ft. of trackway. 



> 



18 in. ti)24 in. wide, 
4 in lo 5 in. thick. 



Road from Albany west to Schenectady, X. Y., 1901. 
Built by Turnpike Company in 1834. 




5 in. w iile, 3 in. deep 6 in. thick 

Road west from Kingston, Ulster Co., X. Y., 1902. 
Built b}' Turnpike Company in 1S62. 

STONE WHEEL-TRACKS. 
22 



STONE WHEKL-TRACKS. 

broken have from time to time been re})lacecl l3v old 
blue-stone curbs from Albany. 

About 1862, a system of similar wheel-track roads 
was begun in Ulster County, N. Y., when I)a\is 
Winne built a blue-stone track-way as a toll-road from 
Kingston eight miles up the Delaware and Ulster 
Valley to the blue-stone quarries in the Catskill moun- 
tains. This proved to be so successful that branches, 
and other roads of the same sort, were soon built and 
are still in decreasing use. 

The ease of traction on these smooth slabs led to 
an increase of the loads drawn upon them, until eight 
tons has been and is an ordinary load for two horses to 
bring from the quarries in the hills to the wharves at 
Kingston and Rondout. Loads of twelve to fourteeii 
tons drawn by three horses are now of daily occurence, 
and loads of seventeen tons actual weight have some- 
times been drawn by four horses : all loads being 
weighed to determine the tolls. 

These great loads were formerly carried upon nar- 
row tires of one and one-half to two inches which 
speedily cut furrow^s in the hard stones, so that the 
slabs six to ei^ht inches thick were cut throuHi in 
three or four years and required renewal. Along the 
roadsides are now many such slabs cut nearly through 
and laid aside, w^hile all the slabs which are in use show 
furrows ranging from one to five inches deep and three 
to four inches wide. 

A railroad now parallels and crosses this highway 
reaching the quarries or passing near them. Wide 
tires, \vhich are required in the river cities and towns, 
are used on all w^agons carrying these loads, so that 
four-inch slabs of blue-stone are now used for renewals 

23 



CITY ROADS AND PAVEMENTS. 

of the wheel-tracks and cost ten cents per running foot 
of slabs twenty-four inches wide. The actual cost of 
the original wheel-track road built in 1862 was about 
$3,000 per mile ; the high prices induced by the War 
increasing the cost fifty per cent over the contract-price 
made in 1861. 



24 



MODERN PAVEMENTS. 



Comparative loads. — In considering the desirability 
of the different road-surfaces and pavements, it may be 
noted that a team drawing one ton on a good dirt road 
can, with the same effort, take two tons over a good 
macadam surface. Passing from this to a good block- 
stone pavement, six tons could be drawn as easily, and 
this load can be increased to eight tons on good wood- 
block or new vitrified brick, or to ten tons on a bitu- 
minous macadam or an asphalt pavement. 



COST OF PAVEMENTS. 

The following table shows the conditions and costs 
in 1894 in the 32 cities named, 8 of which had wood- 
block pavements, 27 of which had sheet-asphalt pave- 
ments, and all of which had block-stone, six having 
sandstone, and the rest granite. The conditions and 
costs in 1901 are shown in detail in the. several 
chapters. 



25 



CITY ROADS AND PAVEMENTS. 



TABLE. 





Block-Stone. 


Sheet 


Wood. 


CITY AND STATE. 


Granite. 


Sandstone . 


Asphalt. 


Cedar-block. 




Cost, 
Sq. Yard. 


Cost, 
Sq. Yard. 


Miles. 


Cost, 
Sq. Yard. 


Miles. 


Least 
Cost. 


Albany, N. Y 


$2 90 

3 37 

1 49 

3 90 

2 33 






$3 12 

2 75 

3 00 

3 30 
3 00 
3 50 

2 90 

3 CO 
2 54 

2 35 

3 20 

2 55 
2 80 

2 93 

2 75 






Allegheny, Pa 

Atlanta, Ga 
















Boston, Mass 




4 
II 

150 

24 






Brooklyn, N. Y 

Buffalo, N. Y 








$3 25 




Chicago, 111 


3 00 

4 20 

3 71 

3 40 

4 25 
2 74 


648 


$1 10 


Cincinnati, Ohi) 




Columbus, Ohio 




II 

4 






Denver, Col 








Detroit, Mich 








Kansas City, Kan .... 

Kansas City, Mo 




2 
16 


26 

43 
47 
63 


I 50 

I 35 

I OS 

76 


2 90 


Milwaukee, Mis 


2 Z7 

1 b; 

2 40 

4 75 

3 50 
2 32 


Minneapolis, Minn 

Nashville, Tenn 




2 




New Orleans, La 




8 
52 
23 


3 65 
3 00 
2 68 






New York, N. Y 








Omaha, Neb 




38 


I 52 


Oswego, N. Y 


2 45 


Philadelphia, Pa 

Pittsburg, Pa 


2 41 

2 38 

2 00 

3 25 




2 50 

3 35 














Portland, Me 










Providence, R. I 






265 
2 60 






Rochester, N. Y 


J I 90 ^ 
)3 00 ^ 


9 






San Francisco, Cal 


2 GO 

2 05 

1 15 

3 56 
3 20 

3 15 

2 08 






St. Paul, Minn 






2 70 

2 45 
2 50 

1 9S>^ 

2 25 


30 


I 10 


Syracuse, N. Y 

Toledo, Ohio 


3 00 


10 

125 








Utica, N. Y 


2 50 






Washington, D. C 

Wilmington, Del 






1 






Average of prices 


$2 90 


$2 71 




$2 81 • 




$1 19 



PAVEMENTS FOR STEEP GRADES. 

In selecting a pavement for a given street of which 
the grade cannot be improved, the choice will often be 
limited by the fact that the grade is too steep to permit 
the use of a pavement which might otherwise be 
preferred. 

26 



PAVKMKNTS FOR STKKP (;RA1)KS. 

The most uscfui information on tlic sul^jcct can he 
obtained from the teamsters and ]u)rsemen of cities in 
which different pavements on varying grades liave 
been in use. If it is generally agreed that certain 
pavements are shunned by teamsters because their 
horses slip and fall when going down a certain street 
with a load, it will evidently be unwise to repeat the 
construction of the same kind of pavement with ec[ual 
slope in a similar climate. 

Under the headings of "Asphalt," "Brick," and 
" Broken Stone," there are given numerous instances 
of extremely steep grades upon which these pavements 
are actually built in various cities named. Examina- 
tions of these may furnish to the observer conclusive 
reasons for or against copying them, or may suggest 
changes in detail which w^ould give better results. In 
examining these steep grades, it should be borne in 
mind that the selection of a pavement for a given street 
may have been made directly or indirectly by the prop- 
erty owners, who have not necessarily chosen the pave- 
ment best suited to attract traflfic, but w^ho, preferring a 
quiet street, sometimes select a pavement which trafHc 
will shun. 

SJieet Asphalt, — The practical limit of slope for busi- 
ness streets paved with asphalt is 4 feet per 100 feet, 
though any slope steeper than 3 feet per 100 feet is 
not advisable on a main thoroughfare. 

On residence streets grades as steep as six per cent, 
are common, and much steeper ones often occur as 
shown on page 118: The residents accepting th.e incon- 
venience resulting from a fev\^ da\'S of icy roadway 
because of the many and great advantages during the 
rest of the year. 

27 



CITY ROADS AND PAVEMENTS. 

On semi-business streets having steep grades, it is a 
common and good arrangement to lay a sixteen feet 
asphalt roadway in the center, with an 8-foot strip of 
block-stones or chamferred bricks, or grooved-joint 
wood blocks, on each side. In Syracuse, N. Y., on East 
Genesee street, and on Bellevue avenue, this was done 
in 1897-8, using Medina sandstone blocks. In some 
cases where this has been done, the asphalt has been 
used almost exclusively. 

Even on flat streets, however, in cold, misty weather, 
horses slip badly, so that in Washington it is common 
to remove the shoes from horses in winter because the 
hoofs slip less. In Brooklyn, on Christmas, i9oi,many 
delivery-wagon horses were seen with burlaps tied over 
their hoofs to give foot-hold on the asphalt. 

There will be parts of two or three days during most 
winters when this difficulty will occur with both asphalt 
and brick, both on steep and on level streets unless 
sand is strewn. 

Vitrified Brick. — No complaints are made of slip- 
ping upon grades of five per cent, but these will be more 
or less slippery as soon as this slope is exceeded, with- 
out regard to ice. Observations show that horses 
begin to slip on brick as soon as the grade reaches six 
per cent, and that for any slope over five per cent it 
will be advisable to use special brick having a beveled 
top affording a foot-hold in the joints, which should be 
filled with asphaltic cement and sharp sand. With 
this precaution vitrified brick can be used on slopes as 
steep as are shown on page 98. 

Creosoted Wood Block, — The same general condi- 
tions apply to these as to asphalt for the grades less 



28 



PAVEMENTS FOR STEEP (iRADES. 

than three per cent, ])rc)\'iclecl sliarp sand is strewn o\'er 
the surtace when needed, as for asphalt. 




For grades steeper than three per cent, the special 
grooved joint here shown in detail is filled with 
asphaltic cement and coarse sharp sand, and this gives 
as good a foot-hold as grooved brick. 

Block Stone. — This may be used in its ordinary form 
upon slopes less tlian ten per cent, but for this slope 
and greater, the blocks should have chamfered tops 
and special joints to give better foothold. The best 
manner of construction is detailed on page 6i. 

Broken Stone. — The maximum grade of macadam is 
fixed rather by the difficulties of maintenance than 
by conditions which govern the other pavements. 
Any grade steeper than five per cent offers increased 
difficulties from the wash of storm-water, although 
many instances are given on pages 164-166, where 
these actual steep grades were accepted l^y tlie engi- 
neers who built these roads as being unavoidable 
features whicli would ha\e been changed if possil)le. 

29 



CITY ROADS AND PAVEMENTS. 

Bititininoiis Macadam. — Aside from the general 
merits of this new construction described on page 131, 
bituminous macadam seems specially adapted to meet- 
ing the difficulties which have heretofore attended or 
prevented the use of ordinary macadam on steep grades. 
While it presents the rough surface necessary for a 
secure foot-hold on steep slopes, it does not give any 
chance for toe-calks to loosen it or for storm-water to 
gully it, and these features specially commend it to 
experienced and critical road-builders like the one 
quoted on page 13 7. 

CROWN OF PAVEMENT. 

The ideal road-surface for a rainless climate would 
be flat, but the practical road-surface for all weathers 
must be curved or " crowned," in order to quickly shed 
water to the gutters. This is the sole reason for giv- 
ing a " crown," and it is therefore logical to reduce the 
amount of curvature when the slope of the street gives 
the needed drainage. 

To suit the crown to the slope, engineers have made 
frequent use of the formulae devised in 1898 by Andrew 
Rosewater, M.Am. Soc. C. E., city engineer of Omaha, 
Neb., by which the crown is computed for any width 
and any grade : the amxount of crown decreasing as 
the slope increases. 

The 1898 forrauhe are as follows : 

For Brick, Stone and Wood block := C = }^ {20-f) 

1600 ^ 

For Sheet-asphalt, C = ^ (9-/) 

C =: crown of pavement in feet, 
W = distance between curbs in feet, 
_/= grade of street in feet per 100. 

30 



CROWN OF PAVEMENT. 
Standard Crowns i;v For-mii-.k oi" 1S98. 







For Block- 


STON E 


, Brick and Wood-hlock 




Distance 




Crown 


given 


in hundredths of feet. 






Curbs 




Grade of street in feet per hundred. 






in feet. 
























Level. 


1 


2 


3 


4 


5 


6 


7 


8 




20 


25 


24 


23 


21 


20 


19 


18 


16 


15 




25 


32 


31 


29 


27 


25 


24 


2 2 


21 


19 


-^ 


30 


38 


36 


34 


32 


30 


29 


27 


25 


23 


«J 


35 


44 


42 


40 


38 


35 


33 


31 


29 


27 


C U 
D ^ 


40 


50 


48 


45 


43 


40 


3^ 


35 


33 


30 


"«5 


45 


57 


54 


51 


48 


45 


43 


4"- 


37 


34 


ia 


50 


63 


60 


57 


54 


50 


47 


44 


41 


38 


00 u; 


55 


69 


66 


62 


59 


55 


52 


48 


45 


42 




60 


75 


72 


68 


64 


60 


57 


53 


49 


45 


r s 


65 


87 


78 


74 


70 


65 


61 


57 


53 


49 


0-^ 


70 


S8 


84 


79 


75 


70 


66 


62 


57 


53 


dj 


75 


94 


90 


85 


80 


85 


71 


66 


61 


57 


IT. 


80 


100 


95 


90 


85 


80 


75 


70 


65 


60 







For Sheet-Asphali 


■ 


Distance 


Crown given in hundredths 


3f feet. 


BETWFFV 






Curbs 


Grade of street in feet per 


hundred. 


in feet. 
















Level. 


1 


2 


3 4 


5 




20 


30 


27 


23 


20 


17 


13 


a; 

£ 

tr. 


25 


38 


33 


29 


25 


21 


17 


-^ 


30 


45 


40 


35 


30 


25 


20 


■^ u 


35 


53 


47 


41 


35 


29 


23 




40 


60 


54 


47 


40 


34 


27 


^ xn 


45 


68 


60 


53 


45 


38 


30 


ta 


50 


75 


^7 


59 


50 


42 


33 




5. J 


83 


73 


64 


55 


46 


37 


- > 


60 


90 


80 


70 


60 


50 


40 




65 


98 


87 


76 


65 


54 


43 


^0 


70 


105 


94 


82 


70 


59 


47 


(U 


75 


113 


100 


88 


75 


63 


50 


CO 


80 


1 20 


107 


93 


80 


67 


53 





31 



CITY ROADS AND PAVEMENTS. 

1902 /'(^rw?^/^^.— Observations since 1898 have con- 
vinced Mr. Rosewater that American sheet-asphalt 
pavements should have the maximum crown practi- 
cable for traffic, as a means of protection against the 
standing of water in the small surface depressions. 

Observation also suggested to him an increase of 
crown of all pavements on various gradients because, 
under the 1898 formulae, the pavements on grades 
varying from three to eight per cent failed to shed 
water to the gutters quickly enough to prevent freezing 
in sleety weather, or to avoid its spreading in warm 
weather. 

To meet these objectionable conditions, radically 
different formulae have been devised in 1902 by Mr. 
Rosewater as substitutes for those of 1898. 



The \()02 forTHidce are as foiIo7us : 

For brick, stone-block, wood-block and com-") W (100 — 4^) 
pressed pAiropean rock-asphalt, - " ) ^°°° 

For American sheet-asphalt ~) ^ W (100—4 /) 



}- 



(composed of sand and asphalt or of compressed . .^q^ 

natural sand-rock), ---.-' 

C ^^ crown of pavement in feet, 
W = distance between curbs in feet, 
f = grade of street in feet per 100. 



32 



CROWN OF PAVKMKNT. 



Standard Crowns by Formll/E of 1902. 





For Block-stone, Brick and Wood-block 




Distance 


Crown given in hundredllis f 


)f feet. 






BETWEEN 
















Gurus 


Grade of street in feet per " 


lundred. 






in feet. 


















Level. 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


13 


14 


20 


33 


3^ 


31 


29 


28 


27 


25 


24 


^Z 


21 


20 


19 


17 


16 


15 


25 


42 


40 


38 


?>i 


35 


1>7> 


32 


30 


28 


27 


25 


23 


22 


20 


18 


30 


SO 


48 


46 


44 


42 


40 


38 


36 


34 


32 


30 


28 


26 


24 


22 


35 


'IS 


56 


54 


51 


49 


47 


44 


42 


40 


Zl 


35 


'i2> 


30 


28 


26 


40 


67 


64 


61 


59 


56 


53 


51 


48 


45 


43 


40 


31 


35 


32 


29 


45 


7S 


72 


69 


66 


63 


60 


57 


54 


51 


48 


45 


42 


39 


36 


33 


50 


83 


80 


n 


IZ 


70 


67 


63 


60 


57 


53 


50 


47 


43 


40 


31 


55 


92 


88 


84 


81 


11 


IZ 


70 


66 


62 


59 


55 


51 


48 


44 


40 


60 


100 


96 


92 


88 


H 


80 


76 


72 


68 


64 


60 


56 


52 


48 


44 


65 


108 


104 


100 


95 


91 


87 


82 


78 


74 


69 


65 


61 


56 


52 


48 


70 


117 


112 


107 


103 


98 


93 


89 


84 


79 


75 


70 


65 


61 


56 


51 


75 


121; 


120 


III 


1 10 


IDS 


100 


95 


90 


85 


80 


75 


70 


65 


60 


55 


80 


133 


128 


123 


117 


112 


106 


lOI 


96 


91 


85 


80 


75 


69 


64 


59 







For Shket-Asphalt 


Distance 




Crown given in hundredths of feet. 


BETWEEN 






Curbs 




Grade of street in feet per hundred. 


in feet. 








Level. 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


20 


40 


38 


31 


35 


34 


32 


30 


29 


27 


26 


24 


22 


21 


25 


SO 


48 


46 


44 


42 


40 


38 


36 


34 


32 


30 


28 


26 


30 


60 


58 


55 


53 


50 


48 


46 


43 


4' 


38 


36 


34 


31 


35 


70 


67 


64 


62 


59 


56 


53 


50 


48 


45 


42 


39 


36 


40 


80 


11 


74 


70 


67 


64 


61 


58 


54 


51 


48 


45 


42 


45 


90 


86 


83 


79 


76 


72 


68 


65 


61 


58 


54 


50 


47 


50 


100 


96 


92 


88 


84 


80 


76 


72 


68 


64 


60 


56 


52 


55 


1 10 


106 


lOI 


97 


92 


88 


84 


79 


75 


70 


66 


62 


57 


GO 


120 


115 


1 10 


106 


lOI 


96 


91 


86 


82 


11 


72 


67 


62 


65 


130 


125 


120 


114 


109 


104 


99 


94 


88 


83 78 


13 


68 


70 


140 


134 


129 


123 


118 


112 


106 


lOI 


95 


90 1 84 


78 


13 


75 


150 


144 


138 


132 


126 


120 


114 


I08jI02 


96, 90 


84 


78 


80 


160 


154 


147 


141 


134 


128 


1 22 


115 109 102 


96 


90 


83 



?>?> 



CITY ROADS AND PAVEMENTS. 

Under the heading of "Asphalt," pageiiS, and 
" Brick," page 95, will be found the record of the actual 
present practice for crown on level grades and 30 feet 
width in the cities named. 

Form of Crowjt. — The form of crown should be a 
parabolic curve nearly flat at the center, for traffic, and 
sloping more quickly toward the sides, for drainage. 

When the amount of crown has been computed 
from a formula or a table, or when an experienced 
engineer has preferred to determine it arbitrarily, 
as is very often well done, the form of the curve can 
be determined thus for any width or crown : divide 
the space from center to curb into twelve equal 
parts. Take the center ordinate, or total "crown," 
as unity; then the successive ordinates, measured up 
from the base-line, will be: At center, i.oo, .99, .97, .94, 
•89, .83. -75. -66, .55, .44, .30, 16, .0 at curb. Or 
stretch a line from curb to curb on level with the 
center, and measure down the corresponding amount. 
Thus if the width is 30 feet from curb to curb, and the 
crown has been determined to be half a foot, the ordi- 
nates measured down at intervals of i % feet will be in 
inches and decimals. At the center o inches — 0.06, 
0.18,0.36,0.66, 1.02, 1.50, 2.04, 2.70, 3.36, 4.20, 5.04, 
6.00 inches at curb. This shows a side-slope of about 
five per cent on the third next the curb. These fig- 
ures may be useful in making a template for fixing 
the curve of a pavement-surface, or for forming the 
sand-cushion of a brick pavement as described on 
page 95- 

For Macadam, it is usual to consider that the con- 
ditions to be met are reversed, and it being necessary 
to prevent storm-water from following the road-surface, 

34 



CITY ROADS AND PAVEMENTS. 

the " crown " for macadam is increased as the slope 
increases; one-half inch per foot being usual on level 
grade, and a maximum of three-quarters inch per foot 
on steep slopes, increasing to one inch on excessive 
slopes. This produces in theory a ridge in the center, 
with a straight slope of 5 ^ inches on each side for a 
level 22 foot roadway. But in practice, the roller flats the 
central " ridge " down, and produces a curve which is 
flat in the center and slopes most at the sides, which is 
the form desired. 

FALLS ON DIFFERENT PAVEMENTS. 

As to the relative liability to accidents from slipping 
of horses' feet upon different pavements, observations 
were made for Captain (now General) Francis V. Greene, 
M. Am. Soc. C. E., during a period of six months on 
thirty-six various streets in ten different cities, viz.: 
New York, Philadelphia, Chicago, Boston, St. Louis, 
New Orleans, Washington, Buffalo, Louisville and 
Omaha. The result of these observations, and of 
similar ones made by Col. William Haywood, M. Inst. 
C. E. in London, by George F. Deacon, M. Inst. C. E. 
in Liverpool and by French engineers in Paris, were 
read before the Am. Soc. C. E. on December 16, 1885. 
Over 800,000 horses and 81,000 miles of travel were 
observed in the ten cities of the United States, with 
the result of showing that a horse may travel, for each 
fall that occurs — 

272 miles on wood-block pavement. 

413 miles on granite-block pavement. 

583 miles on sheet-asphalt pavement. 
These results in the cities of the United States dif- 
fer radically from those obtained for Colonel Haywood, 

36 



CULVKRTS. 

in London, wIktc it was required that liorses should 
be sniootli-sliod, instead of liaving tlie sliarp toe-calks 
which are generally used in the United States, and 
where European rock-asphalt is used instead of Ti-ini- 
dad asphalt and sand. The results observed in Lon- 
don were — 

446 miles on wood-block pavement. 

132 miles on granite-block pavement. 

191 miles on sheet-asphalt pavement. 

CULVERTS. 

To carry water beneath a roadway, culverts are 
variously built of cast-iron pipes, of masonry, of concrete 
and of double-strength vitrified pipe. 

The bottom-line of culverts is usually fixed at the 
bottom-grade of the side-ditches so that the available 
height is limited, and large waterway is often obtained 
by using two, and sometimes three, parallel lines of 18, 
24 or 30-inch ])ipes. 

If the ditch drains a hillside having a southern 
exposure, the midday sun of winter will supply a trickle 
of water which will freeze at night, and under this con- 
dition such pipe culverts will soon freeze solid and 
sometimes burst. 

For most conditions, box-culverts of rubble masonry or 
of monolithic concrete with embedded expanded metal 
in the covers, are much preferable to pipes, being less 
ready to freeze and less liable to be dama^^ed if frozen. 

For equal areas of waterway and depending upon 
the local conditions of stone-sup]:)ly and freight rates, 
the relative costs will usually be in the order fu'st 
named above. 

When the span of a masonry culvert is two feet or 
more and 6-inch to S-inch cox'er-stones are used, thev 

37 



CITY ROADS AND PAVEMENTS. 

should be carried on suitable I-beams placed two feet 
centers, in order to carry ordinary traffic safely. If 
there is height enough a rough stone arch may be best 
and cheapest. 

CURBS. 

Curbs should be set or re-set before beginning the 
pavement of which they are a necessary adjunct. The 
trench for the curb should first be cut and graded, and 
sub-drained if needed, and if concrete foundation for the 
curb is proposed, the curb-stones should be accurately 
aligned and graded upon fragments of stone, around 
and over which the concrete is to be formed and 
tamped : the pavement-base, if any, and the pavement 
itself being afterward formed against the face of the 
curbs. 

Curbs are used of various materials which are some- 
what as follows for the different sections of the United 
States; there being noticed a general tendency toward 
the use of concrete. 

Kinds.— ¥ or the New England States, granite and 
also concrete. For New York and the cities along the 
Hudson and the coast, and for Washington in part, 
"bluestone" (a tough sandstone) from Ulster county, 
N. Y., and limestone and also concrete, of which there 
was built 202 miles in the Borough of Brooklyn during 
1900. For central, southern and western New York, 
and for adjacent Ohio and Pennsylvania, Oxford " blue- 
stone," from Chenango county, N.Y., and Medina sand- 
stone, from Orleans county, N. Y., and limestone, and 
also concrete. 

For the western and southern cities, granite, and 
sandstone from Kettle River, Minn., and from Berea, 
Ohio, and from Colorado, and also concrete, the latter 

38 



CURBS. 



being mucli used in Chicago, St. Paul, and Cleveland. 
Brick curbs are used with brick pavements in Louisiana 
and Texas, and have been observed in two northern 
towns in connection with brick gutters for macadam- 
ized streets. These were special brick, 2^-inch by 
4^-inch by 8>^-inch, with one corner rounded, set 
on end upon concrete with the edge toward the road- 
way and showing 4>^ inches above the paved gutter: 
they seemed to be poor substitutes for stone or con- 
crete, as the material is unsuited for the purpose : this 
opinion is confirmed by Willis Fletcher Brown, con- 
sulting engineer of Toledo, Ohio, whose extended 
experience with brick pavements is well known. 

Sizes. — The dimensions of stone curbs vary in the 
cities from sixteen to twenty-four inches for depth, five 
to six inches for thickness, and three to five feet for 
length. The top is always beveled to take the slope 
of the sidewalk to the gutter. 



Coo c rate 







A^phQlt pavement 

with 
CornbinecJ c<^rt) and guttfei* 

Concrete curb is usually mioulded in place in uniform 
lengths, varying from four to ten feet, preferably five 
feet, with }i inch joints formed by the removal of tem- 
porary steel templates. It is often made in combination 
with a 1 2-inch to 15-inch gutter, and it is recent and 
good practice to add a cast iron or a steel guard-strip 
or " rub-strip," anchored two inches into the concrete 
by a 2-inch by ^-inch perforated web, and showing a 

39 



CITY ROADS AND PAVEMENTS. 

rounded flat surface of i >^ to 2 inches on the outer top 
edge, to protect against the impact of wheels. 

Corners are usually curved on radii varying from four 
feet to nine feet; the former preferred for streets of 
moderate traffic. 

COST. 

Straight curbs set cost about as follows, with thirty 
per cent to fifty per cent added for curves: — 

Granite, 50 cents to 90 cents and in some cases 
$1.25 per linear foot. Ulster or Oxford bluestone, 40 
cents to 80 cents and in some cases ^i.oo per foot. 
Medina or Berea sandstone 35 cents to 70 cents. 
Concrete usually costs from 40 cents to 50 cents, with 
35 cents added for a combined gutter, though combined 
curb and gutter have been built for 50 cents. 

The prices vary widely with the freight-rates and the 
local conditions. 

CAR TRACK CONSTRUCTION. 

When any of these pavements are to be built on a 
street containing car-tracks, special attention must be 
given to the reconstruction of the track and to the 
details of the pavement next to the rails. The pave- 
ment between the rails, and for two feet on each side 
of them, should be built by the railroad company under 
the plan and direction of the city engineer, or this 
should be done by the city at the expense of the rail- 
road, as in Rochester, N. Y. The methods there used 
in 1900 are shown in the picture here given. 

This construction with heavy rails is necessary to 
make the track-structure as rigid as possible, and this 
is so well accomplished in 1901 that sheet-asphalt is 

40 



CAR TRACK CONSTRUCTION. 

laid in actual contact with both sides of the rails, upon 
which exceptionally heavy cars pass without cracking 
the asphalt. This is seen at the best in Huffalo, N. Y., 
where the rails are electrically spliced in place, by 
wielding three-inch by one-inch by fifteen-inch steel 
plates on both sides of each joint, forming continuous 
ninety-pound rails for great lengths. Joints are cast 
with molten iron with similar effect at Chicago, Brook- 
lyn and Minneapolis, and many other cities where the 
authorities and the railroads work together to get the 
best results in their pavements. 




TRACK AXD PAVEMEXT COXSTRUCTIOX, ROCIIEvSTER, X. Y., t.xx). 

Medina sandstone block pavement on six-inch natural cement concrete base, and 
trolley-railway track-construction on concrete foundations. Three-inch porous tile 
beneath concrete and leading to sewers ; Ties two-feet centers, on concrete five 
inches thick, with twelve inches of concrete between the ties ; Xine-inch full-grooved 
steel girder-rails, bonded, resting upon the ties and upon twelve inches of concrete 
between the ties. 



41 



CONCRETE BASE FOR PAVEMENT. 



A concrete base, four to six inches thick, is desirable, 
whether the wearing-surface is to be of asphalt, or of 
creosoted wooden blocks, or of vitrified brick, or of 
stone blocks. The wearing-surface will need repairs 
and renewals, but a properly-made concrete base will 
be permanent, and will always increase in strength and 
solidity. It is specially needed wherever the street is 
of recently made ground, or where it was formerly 
swampy or unstable, or where traffic is expected to be 
heavy, unless an old stone pavement is in place to serve 
as a substitute. 

SUBGRADE. 

Before forming the subgrade to receive the concrete 
base, all present and prospective sewer, water and gas 
and subway connections should be made and extended 
under the curbs, and all old and new trenches should 
be tested with a ten-ton roller, and depressions should 
be filled and wetted and tamped until solid. 

HYDRAULIC CEMENT. 

The manufacture of American Portland cements has 
increased from one-third of a million barrels in 1890 to 
ten million barrels in 1900, and the manufacturers have 
meantime raised their standards, improved their pro- 

42 



CEMENT TESTS. 

ducts and reduced their prices to keep pace with tlie 
growing demand for the highest grades which were 
formerly only made abroad. 

The differences in price between the high-grade 
reliable cements and the low-grade uncertain ones are 
comparatively small, and the poor cements will disap- 
pear from the market when all engineers make tests and 
are guided by the results. 

Good natural cements are still much used, as appears 
from the table at page 56, and they are better than 
low-grade Portland cements, as w^ell as being cheaper. 

CEMENT TESTS. 

The engineer of a small city will seldom have time 
or outfit for the complete tests now usual on large 
works, for which there are needed a special man with 
an expensive equipment installed in a separate room. 

The following described simple tests can be made 
by the engineer himself, with an outfit costing not over 
four dollars and which can be stored in a desk pigeon- 
hole. The tests thus made will be interesting in them- 
selves, and will be effective and convincing aids in 
rejecting most bad cements which may be offered, and 
will also have the preventive effect of causing manu- 
facturers to send their lower grades of cement else- 
where and to send only their best products to the places 
where such tests are probable: — 

First. — For fineness. — Sift three to four ounces of 
cement through a standard test seive of 100 meshes 
per linear inch. Reject cement of which ten per cent 
by weight is retained on the seive. This is conserv- 
ative and the limit may be made smaller, for many Port- 
land cements are now in the market which will leave 

43 



CITY ROADS AND PAVEMENTS. 

less than four per cent. A test by 200-mesh seive with 
a thirty per cent hmit is desirable but takes time. 

Second. — For qztickness of setting. — Make a pat of 
four ounces of neat cement adding one-quarter to one- 
fifth its weight of water and making a putty-like ball 
which can be dropped on the table and retain its form 
without falling to pieces. Press this upon a three bv 
four inch glass plate leaving it half an inch thick in 
the center and sloping to thin edges all around. Note 
time required to take initial set. Reject cement which 
sets in less than twenty-five minutes. It may take three 
hours or more, but it will be better for paving if it sets 
in one hour. The instant of " initial set " is determined 
by noting when the surface will support a four-ounce 
weight resting upon the smooth flat end of a one- 
twelfth inch diameter wire. 

Third. — For soundness. — Use the pat on glass above 
described and note when it sets enough more to make 
it difiicult to indent it with the thumb nail, or when it 
will support one pound on the smooth flat end of a one- 
twentv-fourth inch wire, which mav be considered as 
indicating " a hard set." Then put the pat with its 
glass plate over boiling water until the steam has heated 
them, and then immerse and keep them in the boiling 
water for three hours. Reject Portland cement if the 
pat shows radiating cracks in the center, or shows blow- 
holes on the surface, or curls up from the glass or cracks 
at the thin edges. Good natural cements may fail to en- 
dure this test (which is a severe one), and it may prop- 
erly cause the rejection of some Portland cements which 
would endure it after being " air-slacked " or " seasoned." 

Fourth. — For purity. — Provide a glass-stoppered 
bottle of muriatic acid ; two shallow white bowls or two 

44 



CEMENT TESTS. 

half-inch by six-incli test-tubes, a glass rod and a })air 
of rubber gloves. Put in a bowl or a tube as much 
cement as can betaken on a nickel five-cent piece; 
moisten it with half a teaspoonful of water; cover witli 
clear niuriatic acid poured slowly upon the cement 
while stirring it with the glass rod. 

Puix Portland cement will effervesce slii>:htlv and 
will give off some pungent gas and will gradually form 
a bright yellow jelly without any sediment. 

Powdered Iiniesto7ie or powdered cement-rock mixed 
with the pure cement will cause a violent effervescence, 
the acid boiling and giving off strong fumes until all 
the carbonate of lime has been consumed when the 
bright yellow jelly will form. 

Powdered sand or qnartz or silica mixed with cement 
will produce no other effect than to remain undissolved 
as a sediment at the bottom of the yellow jelly. 

Reject cement which has either of these adulterants. 

Poz^dered slag mixed with cement unfits it for pave- 
ment-work. The adulteration is indicated in the dry 
cement (when coloring matter does not conceal it), by 
a lilac tint, and it is also indicated on the surface of a 
test-pat after drying, by brown and green and yellow 
discolorations. 

A chemical test will show the presence of slag if 
made as follows : 

Provide an ounce of mixture of methylene iodide 
(C H3 L) and benzine, in which the methylene (the 
specific gravity of which is 3.'^' being the heaviest 
organic liquid) is reduced to the specific gravity of 2^^ 
bv addition of benzine. The methylene is uncommon 
and costs a dollar an ounce. 

45 



CITY ROADS AND PAVEMENTS. 

In a half-inch test-tube put half an inch of the dry 
suspected cement and pour in a little of the mixture, 
stirring to a thin grout. Then cork the tube and let it 
stand. If slag is present, it will remain at top while the 
cement will settle to the bottom. The separation can- 
not be seen if coloring matter is present. 

Coloring matter in any cement will show itself in the 
acid test by giving a black or gray color to the resultant 
jelly which would otherwise be yellow. The coloring 
matter may, or may not, be injurious in itself, but its 
presence shows that the manufacturer wished to dis- 
guise the cement, which should be rejected, because 
there are a plenty of good cements which need no 
disguise. 

Weight. — The several kinds of cement differ mate- 
rially in weight and any cement that varies much 
from these average weights should be examined 
specially. 

The standard barrel contains 3.65 cubic feet and the 
standard bag is one-fourth of a barrel. The average 
weight of a cubic foot of packed cement is : Portland, 
104 to 114 lbs. ; puzzolan, 90 lbs. ; natural, 75 to 82 lbs. 
for Eastern and 70 to 72 for Western : The average net 
weight of each per barrel being 375 lbs., 330 lbs., 300 
lbs. and 265 lbs. 

RESULTS. 

These tests will be conclusive as far as they go, 
and will cause the rejection of no good cements. 
The makers of high-grade cements would not object 
to these requirements and would not increase the price 
because of them. 



46 



AC.C.RKC.ATES. 



ISK OF CEMENT. 



The cement in bags or l^arrels slioulcl he deli\'ere(l 
and stored in a tight shed two feet off the dry ground. 

Blending. — The cement should never be used di- 
rectly from any original barrel or bag, because there 
may be more or less damaged or defective packages, 
each of which would thus form a bad spot in the work. 
This chance is wholly avoided by requiring that the 
contents of five packages shall always be blended dry 
in the cement-shed before any is sent out for use, and 
that only this blended product shall be sent out of the 
shed into the work. 

This will not add to the cost, but will merely keep 
the cement-man busier. 

AGGREGATES. 

The aggregates may be crushed from the cheapest 
stone available, though the hardest and toughest is 
preferable. Special care is necessary to see that the 
stone, before crushing, is clean and free from mud 
and clay. Stone unfit for masonry, or for macadam, 
may serve the purpose when it shall be embedded in 
the matrix of mortar in the concrete. 

Crusher-dust as " sand." — The total product of a 
crusher passing through a 2>^-inch screen will give the 
best results, provided that the crusher-dust is consid- 
ered as sand, and that proper allowance is made for its 
presence after determining its quantity. If the stone 
before crushing is not entirely clean, the crusher-dust 
should be excluded by screening. 

Clean gravel and sand may be used in lieu of stone 
with the same provision as to the included sand. 

47 



CITY ROADS AND PAVEMENTS. 

Where neither stone or gravel is available, as in the 
middle West, fragments of brick or of furnace-slag are 
often used as aggregates. 

In any case, the number of cubic yards of loose ma- 
terial for the aggregate will be twelve to twenty per 
cent more than the total cubic yards of concrete ram- 
med in place. 

SAND. 

The sand should be the sharpest and cleanest avail- 
able, preference being given to pit-sand, of which the 
grains vary from fine to course. It will be well worth 
while for the engineer to examine the various sources 
of supply, and to be as careful in its selection as in the 
selection of the cement which is to be mixed with it. 
In a recent case, sand, which seemed fairly good, w^as 
washed and was then found to make concrete which 
w^as one-third stronger than when the sand was used in 
its natural state. Sand containing five per cent of 
loam or of clay is common and should not be used until 
washed. Two per cent will retard the set and per- 
ceptably weaken the mortar. 

PROPORTIONS AND MIXING. 

The proportions measured in loose bulk should be 
one part Portland cement to three parts sand to six 
parts of the aggregate, or one part natural cement to 
two parts sand to four parts of the aggregate. (See 
table at page 56.) 

When the concrete is made by hand, the blended 
dry cement, described on page 47, should be mixed on 
a mortar-bed while dry with the due proportion of dry 

48 



WATER. 

sand, until the color is uniform and no streaks of cement 
can be noticed when the dry mixture is smoothed with 
the back of a shovel. Water (equal in weight to eleven 
to twelve and a half per cent of the weight of the sand 
and cement for Portland cement and fifteen to seven- 
teen per cent for natural cement) is then added gradu- 
ally while mixing until plastic mortar is formed. 

Meantime the rest of the men are measuring, sprink- 
ling and spreading the aggregate in a four-inch layer 
upon the platform (for which a sheet of iron ten feet 
square is the best), and on top of the layer is spread the 
mortar, when the whole is turned with shovels by 
four men while two men work between them with 
specially large hoes. This mixing is continued until 
every face of every particle and fragment is perfectly 
coated with the mortar, requiring hard w^ork which 
must be done rapidly. 

W\\TER. 

It is not important whether the mixing- water is pure, 
but it should not be muddv. 

The required amount of water should vary, as the 
aggregates are more or less moist, so as to give a 
uniform result, for to be either too wet or too dry is a 
grave defect in concrete. 

There is the widest difference of opinion among 
engineers of large experience as to the degree of wet- 
ness which gives the best results. All are agreed tliat 
the surplus mortar must be brought to the surface by 
ramming, after filling all voids. The effectiveness of 
ramming will vary on different works; the ease with 
which the mortar is brought to the surface increases 
with the amount of water, up to the condition where 

49 



CITY ROADS AND PAVEMENTS. 



the concrete is so wet that no ramming is needed; 
which is bad practice, but not uncommon. 

The best practice is to use the least water with which 
the available rammers can be made to bring the mortar 
to the surface. It is futile to try to secure this neces- 
sary result by the persistent ramming of concrete which 
has been mixed too dry, and which it were better to 
remix with more and wetter mortar. There should 
never be enough water to produce free grout, which 
can drain away into the subgrade and be lost. 

MACHINE MIXING. 

Concrete is made better and more cheaply by any of 
the various rotary mixers than it can ever be made by 
hand. It is poor practice to depend upon shovellers to 
proportion the materials, as is often done with continu- 
ous and with gravity mixers. The proportions should 
always be accurately measured. Mechanical mixers, 
operated by steam power, are best adapted to large con- 
centrated masses like dams, foundations and bridge- 





READY TO LOAD. 



LOADED 



abutments, but are not w^ell adapted to forming a thin 
layer spread over a large area, like a pavement-base. 

This condition is particularly well met by a new 
device known as a "dromedary mixer," which consists 
of a two-wheeled cart of which the body is a cylinder, 
which turns with the wheels as the cart is hauled 
along. 

50 



SPREADING AM) RAMMI\(;. 



The proper amounts of cement, sand, stone and 
water, are put into tlie cylinder wliich is closed tightlx", 
and then the cart is hauled to the work where the ])er- 
fectly mixed concrete is dumped in place and spread. 





DUMPING 



The machine is described and highly commended by 
the city engineer of Baltimore, Charles E. Phelps, in 
the Municipal Journal and Engineer, of December, 
1 90 1. 




jT^'^. 



CLOSING 



SPREADING AND RAMMING. 

Set eight-inch boards from curb to curb, supported 
on edge by stakes, and enclosing a space five feet wide, 
within which spread the concrete in a loose layer about 
1% to 7^ inches deep, for a six-inch base, so that a 
one-yard batch will fill about one-third the width of a 
thirty-foot pavement. Ram it at once vigorously until 
all voids are closed, when the surplus mortar will come 
to the surface and the mass will quake slightly under 
the rammers. 

Effective ramming is hard work at which a 
workman should not be kept for more than an 

51 



CITY ROADS AND PAVEMENTS. 

hour, when he should be changed to wheeHng or 
turning. 

MonolitJi. — Each day's work must be a monoHth. 
The spreading and the ramming must be so done that 
each successive batch shall be rammed before the pre- 
ceding and the adjoining batches have begun their first 
set. The stiffness of the concrete after ramming in 
place must be such that the fresh mass will retain its 
form and will not crumble when the boards are removed 
preparatory to filling the adjoining space. Properly 
managed there will be no lines between the batches, 
which will all be merged into one mass. 

Bond. — Each day's work can also readily be bonded 
with the base previously formed, so that the whole will 
be a monolith. Form the end of each day's work on a 
steep two-on-one slope, or with a three-inch step and 
vertical rises, and have the surfaces of the end show 
voids between the fragments of embedded stone to 
afford a good bond. When work begins the next day, 
prepare a pail of thick grout of clear Portland cement, 
and brush it freely over and into the voids of the 
exposed end, just before dumping the fresh concrete 
against it. 

The result of omitting these small precautions, and 
of making a flat slope at the end of each day's concrete- 
work has been known to show, a year afterwards, in 
well-defined waves of an inch or more in height, ex- 
tending from curb to curb of an otherwise perfect 
asphalt pavement. These waves being resultants of a 
slight expansion, or "growth," of the concrete which 
slide upward at all the places, two hundred to three 
hundred feet apart, where the concrete-work for each 
day had ended. 

52 



SETTIXC;. 
SURFACE. 

If it is desired to " float " the surface smooth, as is 
required for pavement-base in Paris, and in Sidne}-, 
N. S. \\\, and for curbs and gutters and for accurately- 
cut wood-block pavements in the United States, the 
surface may be formed of the matrix-mortar without 
the embedded stone-fragments. It is of the first im- 
portance that this surface shall be of the same mortar 
as the matrix of the mass, and be placed at the same 
time and thoroughly blended with it, and that it shall 
not be made of a different or better kind or proportion 
of cement, nor be spread afterwards as a plaster to cover 
a porous or rough surface. Concrete which is consid- 
ered to need plastering should rather be taken out and 
replaced by good work. 

SETTING. 

WMien concrete has been rammed in place, it must 
be kept entirely undisturbed until it sets firmly, which 
should take from four to seven days ordinarily and 
longer in cold weather. 

^?/. — It is of vital importance that the concrete 
should be kept wet during all this time, and that it be 
sprinkled freely at night and morning, and be covered 
from the sun by sand or canvass which will retain the 
water. 

It is a common thing to find experienced foremen 
who fully believe that concrete should ''dry out," and 
many pieces of otherwise good concrete have been ren- 
dered worthless by acting upon this idea which ignores 
the plain fact that "hydraulic" cement requires water. 

Traffic of all kinds, both by foot or by vehicles, should 
be kept from the concrete-base for at least a week if 

53 



CITY ROADS AND PAVEMENTS. 

possible, using planks to cover street-crossings where 
passage-ways must be permitted. 

FREEZING. 

Portland. — For any concrete likely to be soon ex- 
posed to frost, use Portland rather than natural cement, 
and if possible avoid making concrete at all during cold 
weather. Avoid very slow-setting cement for such 
work, and especially avoid using sand or gravel con- 
taining loam or clay, of which even two per cent will 
greatly retard the setting of any cement with which it 
may be mixed. Use a little more cement and a little 
less water than in warm weather. Make special effort 
to prevent the concrete from freezing, at least until it 
takes its first set, and, if possible, for several hours 
afterwards, and also prevent it from thawing after it 
has frozen. While mixing, keep a fire burning in the 
sand pile and another in the stone pile, and heat the 
mixing- water. 

Brine. — Use brine by making a barrel of saturated 
solution of salt, in which keep a layer of free salt show- 
ing in the bottom ; put one-tenth of the contents of 
this barrel, dipped from the bottom, into each barrel of 
fresh water heated for mixing. It is useless to provide 
easily broken salometers which the foremen will not 
use, as this simple plan more readily provides a ten- 
per-cent solution, which will retard freezing and which 
will not injure Portland cement concrete, and which, in 
some cases, will even increase its strength. 

Limit. — Stop work when the cold reaches twelve 
degrees of frost or 20° Fh. If each and all of these 
precautions be observed, good results will be obtained, 
but at greater cost than for work under the normal 
conditions which are the basis of the following table. 

54 



COST. 

COST. 

The present cost of concrete in cities was compiled 
in 1 90 1 in an unusually effective way by F. V. E. Bardol, 
M. Am. Soc. C. E. and chief engineer of department 
of public works of Buffalo, in the following table 
which is republished from " Municipal Engineering." 

These figures and this table do not include the four- 
inch base for five miles of sheet asphalt pavement built 
during 1895 to 1899, in the city of Niagara Falls, N. Y., 
by Walter Jones, city engineer, in proportions of one 
Portland cement, five sand and ten stone, at a total cost 
per cubic yard, in 1897, of ^4.00. The items were: 

i-io cubic yard (or 68^ of a 4-foot barrel) of high grade Port- 
land cement, at $1.75 per barrel $1 20 

5-10 cubic yard of graded pit-sand, fine to coarse, at $1.10 

per cubic yard 55 

I cubic yard of crushed and dust-screened limestone at $1.25 

per cubic yard i 25 

Mixing and placing and ramming " dry "-mixed concrete, 

one cubic yard i 00 

Total per cubic yard , $4 00 

The results were good. 

Portland Cement, — Of forty-two cities, one-third use 
Portland cements in the proportions of one cement, three 
sand and six to seven stone or gravel, at an average 
cost, for twelve cities, of $5.30 per cubic yard. 

Natural Cement. — Two-thirds of these forty-two 
cities use natural cements in the proportion of one 
cement, two sand and four to five stone or gravel, at an 
average cost, for sixteen cities, of $3.85 per cubic yard. 

Cost of Extra Work. — The cost of materials makes 
up seven-eighths of the expense of concrete, so that 
the extra precautions which have here been indicated 
and which may increase the labor ten per cent, will 
add little to the cost per cubic yard of the result. 

55 



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56 



BLOCK-STONE PAVEMENTS. 



Block-stone pavements are forms of tlie most ancient 
pavements, the details of which have been adapted to 
the conditions of modern city traffic. 

Examination of the conditions in the great cities 
which do the best street-work, and which employ the 
best skill to plan and to execute it, shows that block- 
stone pavement of all kinds have long been regarded 
as necessary evils which have only been tolerated 
because they were improvements on the barbarous cob- 
ble-stone pavements which formed the first stepping- 
stones out of the mud, and because better substitutes 
were lacking. There have been obvious advantages 
w^hich have off-set the evident disadvantages, thus 
inducing a more general use of block-stone than is now 
necessary. 

Block-stone pavements are now only desirable for 
steep grades, or for those streets of the largest cities 
where the heaviest traffic exists. There is no such 
traffic in any city of moderate size. 

It has been considered until recent years that blocks 
of the hardest trap rock, or basalt, or granite were best 
adapted to endure the class of traffic which required 
block-stone, and vast sums have been spent in ]:)rcpar- 
ing and laying blocks of granite from Massachusetts, 

57 



CITY ROADS AND PAVEMENTS. 




Clermoxt Avenue, Brooklyn, N. Y. 
Paved about iSSo. 




Eighth Avenue, Brooklyn, N. Y. 
OLD COBBLE-STONE PAVEMENTS. 
Jan. I, 1901, New York City (^Manhattan) had 227 miles of cobble. 
Brooklyn had 300 miles of cobble and defective blocks. 



58 



BLOCK-STONE PAVEMENTS. 

Maine and Vermont, and of diabase trap rock from tlie 
Palisades of the Hudson. 

Pavinof blocks formed of these rocks and laid in the 
usual manner with sand joints, wear in such a way that 
their tops become rounded and polished, giving a poor 
foothold for horses, and forming a surface which collects 
and retains filth, and causes noise, and is injurious to 
public health and comfort : the hardest and finest- 
grained rocks giving the worst results, so that the 
coarser grades of granite have nearly displaced trap 
rock for paving blocks. 



i^"^!±£d 




dond 
Cone ret*. 



Granite povement 



Broadway, New York, has very heavy traffic and has 
been repeatedly paved, from Fifty-eighth street to the 
Battery, five miles, with various forms of granite and 
of trap blocks ; portions of which have needed relaying 
after three years' use, and all of which have been dirty 
and noisy. These conditions are shown to be unnec- 
essary by the fact that during 1900, this block-stone 
pavement was re-set and used as the foundation for 
noiseless sheet-asphalt, which can be kept clean, and 
which is guaranteed to be in perfect condition during 
and at the end of ten years. This was done from 
Fifty-eighth street to Fourteenth street, two and a half 
miles, (and also on sixty other streets in New York,) 
during 1900, and has been extended to Canal street, 

59 



CITY ROADS AND PAVEMENTS. 




Metn.politan Op^ra H. 



BROADWAY, NEW YORK, 1900. 

Looking up from the Casino at Thirty-ninth Street. 

After paving- with sheet-asphalt, in 1900 : Trinidad Lake wearing-surface ; 

Bermudez Lake binder-coat. 



60 



BLOCK-STONE PAVEMENTS. 

one and one-fourth miles, during 1901, and in 1902 will 
be continued one and one-fourth miles to the foot of 
Broadway at the Battery. Many other cities of the ' 
United States have, during the. past ten years, preferred 
to use sheet-asphalt or brick rather than granite blocks, I. 
with the result that the total annual expenditure of the 
cities of the United States for granite block pavements 
has decreased one-half since 1890. 

The ill results obtained from pavements of granite 
and trap blocks are much less marked when the pave- 
ments are formed of blocks of Medina, N. Y., sandstone 
or Kettle River, Minnesota, sandstone. These sand- 
stones wear flat, do not polish, and approach granite in 
their resistance to crushing force, as indicated by the 
followTng statements of average pounds of crushing 
force endured per square inch : — 

Maine granite, 15,000 to 22,000 pounds; Quincy 
granite, 19,500 pounds; average of several of the New 
England granites, 22,000 pounds; Palisades diabase 
trap, 19,700 pounds; Medina, N. Y., sandstone, on bed, 
1 7,500 pounds ; Berea, Ohio, sandstone, 10,250 pounds ; 
Oxford, N. Y., blue stone (sandstone), 13,470 pounds; 
Kettle River, Minnesota, sandstone (after seasoning), 
on bed, 12,300 pounds. 

Paving blocks of Medina sandstone are used to the 
largest extent in the cities of Rochester and Buffalo, 
N. Y., and Cleveland, Columbus and Toledo, Ohio, and 
are quarried along both sides of the Erie canal in 
various places from thirty to fifty miles west of Roch- 
ester, N. Y. The methods are particularly good in 
Rochester and in Cleveland, where the best pavements 
are laid on concrete foundation. At Rochester, the 
half-inch joints are filled with hot coarse sand and hot 

61 



CITY ROADS AND PAVEMENTS. 




Setting Medina sand-stone blocks on six-inch concrete base coveioi wiiii une and 
one-half inches to two inches of sand-cushion. 




Filling joints with coarse sand and hot paving cement. 



BLOCK STONE PAVEMENT, ROCHESTER, N. Y., 1900. 

62 



B LOC K-STON E 1 ' A \' K M K NTS. 

pa\ing cement. '1 lie i^axcmcnts arc built b\' Edwin 
A. Fisher, M. Am. Soc. C. E., as city engineer, and the 
results are the best of which the material is capable, at 
a cost, in May 1901 of $2.48 per scjuare }ard com})leted 
including six-inch foundation of Portland cement con- 
crete. At Cleveland, Ohio a similar pavement is built 
with close joints. 

Paving blocks of Kettle River sandstone are used in 
in Saint Paul and Minneapolis, Minn., and are quarried 
at Sandstone, Minn., about one hundred miles north- 
east of Minneapolis. The method of construction and 
the results are similar to those at Rochester, N. Y., the 
joints being half an inch wide and being filled with 
equal parts of Portland cement and sand. The cost at 
St. Paul in 1900, including six-inch concrete base, was 
$2.45 per square yard completed. 



63 



CITY ROADS AND PAVEMENTS. 



The following table shows the relative use of several 
kinds of block-stone pavements in various cities : — 

Mileage of Block Stone Pavements 
(on basis of 30 feet width or 17,600 square yards per mile). 



CITY. 



Albany 

Atlanta 

Boston 

Buffalo 

Chicago 

Cincinnati . . . . 
Cleveland . . . . 
Columbus . . . . 
New York: 

Brooklyn . . . 

Bronx 

Manhattan . 

Queens . . . . 

Richmond. . 
Philadelphia . . 
Richmond. . . . 

Rochester . 

St. Louis 

St. Paul 

Toledo 

Troy 

Washington . . . 



state. 



N. Y. . . 

Georgia. 
Mass. . . 
N. Y. .. 

Ill 

Ohio... 
Ohio... 
Ohio... 

N. Y. .. 
N. Y. . . 
N. Y. . . 
N. Y. . . 
N. Y. .. 

Pa 

Va 

N. Y. .. 
Mo. ... 
Minn. . , 
Ohio... 
N. Y. . . 
D. C. .. 



i 

Year, j 


1902 


1902 


1902 


1899 


1890 


1902 


1900 


1900 


1902 


1902 


1902 


I901 


I9OI 


1902 


1902 


I90I 


1902 


I90I 


1902 


1902 


1900 



Granite. 


28 


miles 


52 


miles 


114 


miles 


21 


miles 


58 


miles 


2 


miles 


146 miles 


44 


miles 


192 


miles 


29 


miles 


y2 


mile 


340 


miles 


I 


mile* 


70 


miles 


26 miles 


28 miles 



Diabase 
Trap. 



2 miles 



I mile 
7 miles 

87 miles 
7 miles 

y\j- mile 



3 miles 



Sandstone. 



108 miles 



121 miles 
7 miles 



31 miles 

3 miles 
6 miles 



* Also 31 miles of "granite spalls." 



64 



WOOD BLOCK PAVEMENTS. 





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65 



WOOD PAVEMENTS. 



Wood-block pavements, as built since 1900, surpass 
others in freedom from noise, and rank among the best 
in qualities and in cost. 

Of the many forms of wood pavements which have 
been built, only those need be described in detail which 
are still in actual construction : brief descriptions being 
given of the cheaper forms, which are only regarded as 
temporary expedients, and fuller details being shown 
of those latest and most improved forms of wooden 
block pavements which are now ranked with the best 
class of modern work. 

The corduroy roads of a century ago are now best 
known in the tales of our grandfathers, although there 
can yet be found, crossing swamps on the line of the 
old military road which was built in 1 8 1 2 across the 
Adirondack wilderness, from the Mohawk valley at 
Schenectady to Ogdensburg on the St. Lawrence, and 
to Sackett's Harbor on Lake Ontario, sections of 
corduroy road, which are still as sound as when laid, 
having been preserved from decay by the water which 
has usually covered them, although huge forest trees 
have meantime grown up in the old and abandoned 
roadway near at hand. 

The plank roads of a half century ago are nearly 
gone, with the toll-gates which were the objects of their 
beginning and the cause of their ending ; though it is of 

66 



ROUND CEDAR lU.OCK. 

curious interest tliat tliere are still, in 1902, two plank 
roads leading from the westward into the city of 
Albany, N. Y., having five toll-gates on ten miles of 
road ; but these relics of old days are of only historic 
interest, as are the majority of the thirty patented and 
forgotten forms of wood pavements which had their 
rise and fall thirty to forty or more years ago, beginning 
in Boston, Philadelphia and New^ York about 1840 and 
culminating from i860 to 1870, in the "Nicholson 
block," of which a description is now useless. 

ROUND CEDAR BLOCK. 

The well-known round white-cedar block pavement 
came into general use in western cities about 1880, in 
response to an urgent demand for something quick and 
cheap which would last until the abutting lots could be 
sold. This pavement w^as built in different ways in the 
various cities, but it probably has its best form as still 
built in Chicago in 1900. The prepared subgrade of 
the street is covered with two inches of sand, in which 
are embedded, across the street at six feet intervals, 
one-inch by eight-inch pine boards laid flat, as supports 
for the ends and centers of two-inch hemlock plank laid 
lengthwise of the street and close together, forming a 
regular crowned surface. 

The cedar blocks are of sound live w^ood, free from 
bark, not less than four, nor more than eight inches in 
diameter and six inches long. These blocks, unsea- 
soned and untreated, are set on end in close contact, and 
the irregular interstices are rammed full of half-inch to 
one and one-half inch gravel. The surface is then 
flooded twice with coal-tar heated to 300° Fh., using two 
gallons per square yard in all, followed while hot with 

67 



CITY ROADS AND PAVEMENTS. 

a three-fourth-inch layer of clean gravel, not exceeding 
half-inch, which has been screened from that used to 
fill the spaces. 

In 1900, this cost about seventy cents per square 
yard in Chicago, where there was then about 880 miles 
(on basis of thirty feet width) of streets thus paved. 
This being probably somewhat more than the total 
similar mileage in all of the other cities using this form 
of pavement, the relative amounts being in about the 
following order: viz., Detroit, Superior, Duluth, Mil- 
waukee, Minneapolis and Toronto. 

It usually needs renewal in six years and becomes 
impassable in nine years, though the results are some- 
times much better than this. 

Cypress blocks were similarly used in Omaha, Des 
Moines and Kansas City, and failed in two to four 
years. 

BLOCKS ON SIX-INCH CONCRETE BASE. 

Hexagonal blocks of mesquite, 5" deep and 4" to 
8" diameter have been laid at San Antonia, Texas, at 
cost of $2.80 per square yard, including the six-inch 
base. 

Tamarack-blocks, 3" by 5" by 6" have been laid in 
Montreal and coated with hot coal-tar and gravel. 

Redwood blocks, 4" by 6" by 6" seasoned, and boiled 
in asphalt, have been laid in San Francisco and Oak- 
land, California. 

Yellow pine blocks, 4." by 6" by 6" to 10" creosoted 
with twelve pounds per cubic foot, were laid in Galves- 
ton, Texas, in 1895-8. 

Creosoted or " treated " blocks on concrete base are 
recommended for fifteen miles of streets by the board 
of local improvement of Chicago during 1902. 

68 



WOOD BLOCK l'A\ KMEMS. 



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69 



CITY ROADS AND PAVEMENTS. 

Washington cedar blocks, sterilized and creosoted 
with three to four pounds of creosote per cubic foot, 
were laid on about four miles of Indianapolis streets in 
1896, and some are in good condition in 1901. Some 
of the w^ooden pavements built in Indianapolis about 
that time have swollen and heaved badly. 

Oregon red cedar and southern yellow-pine heart- 
wood blocks, 4" by 4" by 9" creosoted with ten pounds 
per cubic foot, were laid in 1899 in Indianapolis at a 
cost of $2.10 to $2.50 per square yard, including base 
and five years guarantee : the joints being filled with 
paving cement of nine parts coal-tar to one part asphalt, 
and the surface being covered with half-inch screenings 
of crushed granite. This is a much more costly pave- 
ment than the others which have been described, and 
is of a high class, as are the later improved kinds 
described on page 74. 

In Paris, pine blocks of several forms, creosoted with 
eight to ten pounds of creosote oil per cubic foot, form 
the greater part of the ninety miles (thirty feet width) 
of wood-paved streets. Wood is preferred as being less 
slippery and less noisy than compressed rock-asphalt, 
and that it is satisfactory in its other qualities is evi- 
denced by the fact that the amount of wood pavement 
in Paris is increased every year. Including the six- 
inch concrete base in both cases, the cost complete is 
about the same as for rock-asphalt, viz., $3.10 per 
square yard. 



70 



AUSTRALIAN HARD-WOOD PAVEMENTS. 



These are the most costly of any of the various 
wooden-block pavements and, therefore, have not been 
laid to any extent in the cities of the United States. 

They have, however, been largely used, and wdth good 
effect, in London, which has wood pavements of many 
kinds to the extent of about 240 miles, computed on a 
basis of thirty feet width. 

The city of Sidney, New South Wales, has many 
miles of wood-paved streets, upon which Australian 
hard woods have been used with most remarkable 
results, which would be incredible if not substantiated 
by the statemicnts of \\\ A. Smith, M. Inst. C. E., and 
also by the report of R. \V. Richard, Asso. M. Inst. 
C. E., the city surveyor of Sidney, and engineer in 
charge of Sidney pavements. Queen street, which has 
an estimated daily traffic of 25,000 tons, was thus paved, 
and the blocks after eight years use, showed a greatest 
observable wear of one-sixteenth of an inch and were 
otherwise in almost as good a state in 1893 ^'^ when 
laid. The original cost was $3.05 per square yard, 
exclusive of foundations, with an annual cost of two 
cents per square yard for maintenance and for daily 
sanding. 

The details of their construction in Sidney are as 
follows : 

71 



CITY ROADS AND PAVEMENTS. 

The foundation, or base, was a layer of one-to-seven 
concrete, formed with a floated smooth surface, having 
a convexity from one in forty to one in eighty, and 
allowed to set for seven days before use. 

This concrete base was six inches thick on solid 
ground and nine inches thick on uncertain ground. 

The pavement which gave the best result was formed 
with seasoned heart-wood blocks of tallow- wood, black- 
butt, and blue gum, red gum, jarrah or karri, each kind 
being laid separately. Each block was formed by cut- 
ting a three-inch by nine-inch plank into pieces six 
inches long, and these blocks were then painted with, or 
dipped in, hot coal-tar and hot wood-preserving oil, and 
stacked for four hours before being set in the work. 
The blocks were set on end with the fibre vertical, 
forming three-inch rows across the street from curb to 
curb, each block breaking joints two inches with blocks 
in the next row. 

To provide for the expansion of the blocks when wet, 
expansion-joints were formed along each side of the 
pavement; these joints being two inches wide between 
the curb and the gutter-course, and an additional one- 
inch joint between the gutter-courses, which were 
formed of blocks set in rows running lengthwise of the 
street. Curbs, eighteen inches deep, were needed to 
resist the thrust which moved twelve-inch curbs. Bet- 
ter results were reached when these expansion joints 
were filled with mastic than when filled with sand or 
with clay puddle. These widths of joint were used on 
pavements sixty-four feet wide and gave good results. 

The best results were obtained when the blocks 
were forced close together on grades up to one in 
twenty and with one-quarter-inch joints on steeper 

72 



AiMEKlCAN HARD-WOOD PAVKMKNTS. 




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73 



CITY ROADS AND PAVEMENTS. 

grades up to one in thirteen, or eight per cent. After 
completing sixty Hneal feet of roadway, the surface of 
the pavement was swept with hot coal-tar and sprinkled 
with hot sand, and again swept with hot tar until the 
spaces were thoroughly flushed with the plastic paste. 

As to the durability of these hard- wood blocks as 
compared with cubical blocks of blue-stone, Mr. Richard 
states that the blue-stone blocks have shown a wear of 
one inch per year, while the hard-wood blocks, laid as 
described and subjected to similar traffic, have shown 
a wear of one-fiftieth {-^\) inch per year. 

Where the joints have been filled with hydraulic 
cement, the results were not as satisfactory as where 
blocks were laid with close joints, but with the con- 
struction described, these wood-block pavements are 
free from the various faults of our cedar blocks and are 
expected to have a minimum life of sixteen years, equal- 
ing asphalt. 

In Melbourne, similar pavement is estimated to last 
fourteen years. Either of these improved methods or 
the more crude ones generally used in this country are 
costly. The final expense of our cheap construction 
being twice as great as for asphalt or for granite blocks, 
and probably much greater than if white oak or some 
similar hard wood were used. 

AMERICAN WOOD PAVEMENTS OF THE LATEST TYPE. 

The valuable qualities of the highest grade of treated 
wood-block pavements have been generally recognized 
especially their freedom from noise; but their extensive 
use in the cities of the United States has been deferred 
by distrust based upon former failures and by the 
excessive cost. The cities seem to have awaited the de- 

74 



AMERICAN WOOD PAVEMENT. 

velopment of some process of treatment of native woods 
which should be less costly than the Australian hard- 
woods just described, and more satisfactory in various 
ways than the former well-known American methods. 

The creosote as ordinarily used is an effective pre- 
servative in itself, but it tends to form an emulsion with 
water, and also to ewaporate half to three-fourths on 
exposure to the sun and the weather. 

To avoid these defects has been the object of two 
recent modifications of the treatment : the one called 
" kreodone-creosote," and the other " creo-resinate." 



75 



CITY ROADS AND PAVEMENTS. 




Concrete base 



Id prugreis, 



Ten-ton roller. Completod pavement. 



MERIDIAN STREET, INDIANAPOLIS, 1902. 
Kreodone-Creosote Wood-block Pavement in progress in March, 1902. 



76 



KREODONE-CREOSOTE PROCESS. 



This consists in impregnating the seasoned selected 
blocks under pressure with ten pounds per cubic foot 
of an oil derived from creosote oil, possessing the origi- 
nal preservative properties with a longer endurance, 
and also having the effect of forming a varnish-like film 
or coating on the outer surface of the wood, protecting 
it from the elements. 

The seasoned blocks are sterilized by subjecting 
them to dry heat of 240° Fh., for eight hours. The 
kreodone-oil is then forced into the fibres of the wood, 
under a pressure of seventy pounds per square inch, 
maintained for two to three hours, or until twelve pounds 
have been absorbed by each cubic foot of the wood. 

In some cases the blocks are laid with the courses 
running diagonally across the street. The cost in 
Indianapolis for blocks four inches deep, has been #2.50 
to $2.70 per square yard of completed pavement, includ- 
ing concrete base, and also including nine years' guar- 
antee and maintenance. 

The cost of the Chicago pavement on Michigan 
avenue, in front of the Auditorium hotel, for blocks 
five inches deep, exclusive of the concrete base, and 
including surety company guarantee for five years, was 
$1.90 per square yard. 

This Chicago pavement and that on North Dela- 
ware street in Indianapolis, were both laid in 1901, 
and will furnish conspicuous examples by which may 
be observed the peculiar qualities of pavements treated 
with kreodone-oil. 

11 



CREO-RESINATE PROCESS. 



A pavement treated by this process has become 
known during 1900 and 1901 by having been laid on 
conspicuous streets in Boston, on Tremont street in 
front of the Parker House and on Harvard Bridge and 
on Beacon street, and in Springfield, Mass., and in New 
Rochelle, N. Y., and on Holliday street, Baltimore, Md., 
where these pavements have been much commended. 

B. T. Wheeler, superintendent of streets of Boston, 
states that the creo-resinate pavement seems the most 




'§t^ H 



f 




TREMONT STREET, BOSTON, 1900. 
Creo-Resinate Wood-blocks, laid in 1900. 



78 



CREO-RESINATK I'ROCESS. 

satisfactory piece of wood-paving in Boston, and tliat it 
is guaranteed to be kept in such condition for ten 
years. As there used, the pavement is noiseless, is 
free from dust, is not sHppery when wet, when laid on 
three per cent grade with the grooved joint shown on 
page 29, can be taken up and re-laid readily, does not 
absorb moisture, and promises to be durable, though 
this can only be assured by the test of time. 

The special features of the creo-resinate process are 
the preliminary treatment in dry heat to kill the germs 
of decay, and the mixing with the creosote of fifty per 
cent of melted rosin which is forced into the fibres with 
the creosote, where it solidifies and seals the pores of 
the wood and prevents the evaporation of the creosote 
or its displacement by water, w^hich can find no 
entrance, so that the pavement does not swell and 
heave when wet. 

The blocks are of Georgia long-leaf yellow-pine 
heart-wood 4" by 8" by 4" deep and are treated in an 
air-tight cylinder by dry heat for five hours, during 
which time the temperature and pressure are gradu- 
ally raised to 285° Fh., and to ninety pounds per square 
inch, when both are gradually lowered and a vacuum 
is produced, followed by hot creo-resinate mixture, 
afterwards forced in by hydraulic pressure of 200 
pounds per square inch, which is maintained until 
twenty-one to twenty-two pounds of the mixture has 
been absorbed by each cubic foot of the wood. 

This is followed, in another cylinder, by hot milk-of- 
lime under the same pressure, in order to fix and set 
the creosote, so that the blocks, when ready for use, 
present a peculiarly solid appearance. 



79 



CITY ROADS AND PAVEMENTS. 

The blocks are then laid, with the grain vertical, 
upon a one-inch cushion of screened sand, covering a 
six-inch concrete base; the blocks are driven tightly 
together at every sixth row and are rolled with a five- 
ton steam-roller until a firm, uniform and unyielding 
surface is made, when the whole is covered temporarily 
with one-quarter inch of clean screened sand. 

COST. 

The cost of this pavement, complete, including a 
surety company ten-year guarantee, for blocks four 
inches deep on concrete six inches deep, varies with 
the local conditions from $3.10 to $3.50 per square 
yard. 



80 



VITKIFIKI) r.RICK. 




Main street, Daj-ton Ohio, paved in 1892. 




Street in St. Louis, paved in 1901. 



', I ^>*.^"^..r"*^" '* 



BRICK PAVEMENTS IN 1901. 



81 



VITRIFIED BRICK PAVEMENTS. 

THEIR USE IN THE UNITED STATES. 



During the past seventeen years there has been a 
steadily increasing use of vitrified brick for the pave- 
ments of the streets of cities and towns in the United 
States, especially of those of moderate size — that is, of 
100,000 inhabitants and less: the larger places wel- 
coming brick as a competitor with sheet asphalt, and 
as affording another means of escape from the intoler- 
able noise and dirt resulting from block-stone pave- 
ments and from the temporary and unsanitary features 
of cedar blocks, while the smaller western towns, with 
characteristic enterprise, have built miles of brick pave- 
ments to displace the natural mud. The total length 
of brick-paved streets in the United States in February, 
1902, is estimated by Wm. S. Crandall, editor of The 
Municipal Journal, at about 1300 miles. 

The following table is reprinted from the first edition 
of " City Roads and Pavements," and shows the modes, 
costs and results in sixty-five cities in 1894: 



82 



VITRIFIED BRICK PAVEMENTS. 




Brick at entrance to Union Station, laid m 1893. 
(Stone-block pavement in foregrovind ). 




Alley paved with brick in 1894. 
BRICK PAVEMENTS, ST. LOUIS, 1901. 



8 



Summary of Reports of Modes of Construction, Cost and 
Results of Vitrified Brick Pavements. 



City and State. 



Atlanta. Ga 

Atchison, Kan 

Alton, 111.. 

Alleghany, Pa 

Bellaire, Ohio 

Binghamton. N. Y. 
Bloomington, HI. . . 

Buffalo, N. Y 

Burlington. la 

Cedar Rapids. la. . . 
Charleston, W. Va. 

Chicago, 111 

Cincinnati, Ohio. . . 

Clinton, la 

Columbus, Ohio . . . 
Connellsville. Pa.. . 
Council Bluffs, la.. 

Davenport, la 

Dayton, Ohio 

Decatur, 111 

Detroit. Mich...... 

Des Moines, la 

Dubuque, la 

Dunkirk. N. Y 

Evansville, Ind 

Findlay, Ohio 

Fort Wayne. Ind . . 

Galesburg, 111 

Hannibal^ Mo 

Hartford, Conn 

Indianapolis, Ind. . 
Jacksonville, 111. . . 
Kansas City, Mo. . . 

Kenosha, Wis 

Keokuk, la 

Lafayette, Ind 

Lancaster, Pa 

Lexington, Ky 

Lincoln, NeV> 

Lock port, N. Y 

Louisville, Ky 

Massillon, Ohio 

Memphis, Tenn 

Olean, N. Y 

Omaha, Neb 

Ottawa, 111 

Peoria, 111 

Philadelphia, Pa. . . 
Providence. R. I. . . 

Quincy, 111 

Rochester, N. Y. . . 

Rockford, 111 

Rock Island, 111.... 

St. Paul, Minn 

Scran ton. Pa 

Springfield, 111 

Steubenville, Ohio. 

Syracuse, N. Y 

Terre Haute, Ind. . 

Toledo, Ohio 

Troy, N. Y 

Washington, D. C. . 
Watertown, N. Y. . 
Wheeling, W. Va.. 
Wilmington, Del.. . 



Miles 
in use 
June, 

181)4. 



Average of prices. 



].l 
2.75 
1 
2 



0.25 

6 

3.33 

7.50 

2 



1 
15 
10 
30 

2 

5 

6 

0.4 
15 

9.6 
10 

1.5 

2.5 

4.5 

4 

2 
12 

1.5 

0.12 

8.7 

9 
10.25 

1 

1.25 

2.50 

0.10 

6 
15 
10 
10 

9 

2.25 

1.50 
10.25 

2.25 

20 

1 

6 

3.14 

1.82 

7 

0.34 

0.10 

5.38 
10 

5 

1 
16.33 

1 

0.25 

0.12 

2 

3 



Cost per Square Yard of "Best 

Work'' on the Foundation 

here indicated. 



Six 

inches 

Concrete. 



$2.19 



1.60 
"2!46' 
'2!75 



2.30 
2.50 



2.00 



2.30 



2.50 
1.70 
1.69 
2.10 
1.70 



1.63 



4.00 
2.35 



2.00 



1.80 
2.25 



2.09 
1.50 



2.65 
2.00 
1.87 



1.75 
2.05 
3.00 



2.30 



2.33 



2.15 



2.50 
2.05 
2.46 



Flat 
Brick or 
Gravel. 



M.75 
2.16 



2.00 



1.60 
1.35 



1.50 
1.60 



1.75 



1.80 
2.05 



1.55 
1.80 



1.75 



1.40 



1.75 
1.62 

2.40 



Broken 
Stone or 
Grave). 



.19 $1.75 



).6l 



1.15 



1.45 
'2!49' 



1.87 
'i!75" 



1.40 
'i!55' 



1,40 



1.80 



1.37 
1.33 



1.35 
1.00 



2.25 
1.05 



1.35 
2.15 



.52 



Filling of 
Joints. 



Paving tar. 
Sand. 
Sand. 
Paving tar. 



Cement grout. 
Sand. 

Cement grout. 
Sand. 
Sand. 
Sand. 

Paving tar. 
Paving tar. 
Sand. 

Paving tar. 
Sand. 
Sand. 
Sand. 

Cement grout. 
Sand. 

Paving tar. 
Paving tar. 
Sand. 

Cement grout. 
Sand. 

Paving tar.- 
Cement grout. 
Sand. 
, Sand. 
Cement grout. 
Paving tar. 
Sand. 



Reported 
Results. 



Satisfactory. 
Excellent. " 



Fair. 



Fair. 

Good. 

Fair. 

Gratifying. 

Fair. 



Sand. 
Sand. 
Sand. 



Paving tar. 
Cement grout. 
Cement grout, 



Sand. 

Paving tar. 
Cement grout. 
Sand. 
Sand. 
Sand. 



Paving tar. 
Sand. 

Paving tar. 
Sand. 
Sand. 
Sand. 

Cement grout, 
Sand. 
Sand. 

Cement or tar. 
Cement grout. 
Sand. 

Cement grout. 
Cement grout 
Sand. 

Paving tar. 
Cement grout 



Satisfactory. 

Fair. 

Good. 

Good. 

Excellent. 

Good. 

Good. 

Good. 

Good. 

Fair. 

Good. 

Satisfactory. 

Good. 



Satisfactory. 

Good. 

Good. 

Perfly. satisfy. 

Good. 

Good. 

Good. 

Fair. 

Good. 

Good. 

Good. 

Good. 

Good. 

Good. 

Excellent. 

Good. 

Good. 

Entirely satis. 

Good. 

Moder'telyfair 

Good. 

Fair. 

Good. 



Good. 

Good. 

Good. 

Satisfactory. 

Indifferent. 

Good. 

Good. 

Good. 

Good. 



Good. 
Good. 
Good. 
Good. 



Satisfactoiv, 



84 



RKACTIOX ACrAINST USK OF P>RI(KS. 
EXTENT OF FFS USK. 

Two to three hundred such cities and towns, as well 
as all of the larger cities, especially Philadelphia, have 
laid more or less vitrified brick pavement, and its use 
is constantly extending, as is shown by the accompany- 
ing table on page 130, compiled by Willis Fletcher 
Brown, city engineer of Toledo, Ohio, showing the 
miles of streets paved with brick and with sheet asphalt 
in thirty cities. 

This table also shows the relative estimation in 
which brick is held as compared with sheet asphalt in 
cities where both ha\'e been used for a period long 
enough for opinion to be formed. 

REACTION AGAINST USE OF BRICKS. 

There has undoubtedly been a reaction in the popu- 
lar desire for brick pavements in some of these cities, 
where people have learned to know what good pave- 
ments are and where brick pavement has been brought 
into close comparison with sheet asphalt, and with the 
best grades of creosoted wood-block pavements in the 
western cities, and more recently by comparison with 
bituminous macadam or bitulithic pavement, in a few 
of the cities of the east. 

The excessive and peculiar roaring noise produced 
by the passage of light wagons over some brick pave- 
ments is objectionable on residence streets, and on 
some streets having heavy traffic there have been 
poor results as to durability. Much discredit has also 
been thrown upon the use of vitrified brick by the care- 
less and ill-judged manner in which many manufac- 
turers have sent out irregularly and imperfectly burned 
brick. These have been laid by incompetent contrac- 

85 



CITY ROADS AND PAVEMENTS. 

tors, under inexperienced city officials, and have thus 
caused the needless failure of many pavements, thus 
stopping further extensions and preventing other cities 
from using brick at all, to the great gain of the sheet- 
asphalt companies, and with the effect of encouraging 
the introduction of bituminous macadam, creo-resinate 
wood blocks and other high-grade pavements which 
are free from these defects and which have not yet had 
time to develop other defects which may be peculiar to 
themselves. 

REGION OF PRODUCTION. 

The production of vitrified paving brick in 1894 
was in a measure restricted within two regions of Penn- 
sylvania and Ohio on the southwest and Indiana and 
Illinois on the west, w^hich produced the special quality 
of material for forming paving bricks, which differ 
entirely from ordinary building bricks in both their 
material and mode of manufacture and in their qualities ; 
the name being a misleading one, as they are not brick 
but tile, and are not actually vitrified, but are fused. 

There are now a number of places outside these 
limits where paving bricks are produced in large quan- 
tities, one of the large plants being on the Hudson 
river at Catskill, from which have been furnished bricks 
for pavements in 112 cities and towns, nine-tenths of 
which are in seven of the eastern states, and the rest 
are in six of the southern states. The material of 
these bricks is low-grade iron ore, shale and clay, which 
are ground to a powder and mixed in proper propor- 
tions and formed into repressed bevelled-edge vitrified 
paving bricks and blocks, which compare well with 
others, and w^hich have been used for most of the brick 
pavement in Albany, N. Y., with good results. 

86 



CHARACTERISTICS. 

Other well-known kinds of high-grade paving mate- 
rials are the Mack bricks and blocks, made at very 
large works, located at New Cumberland, W. Va., 
fifty-six miles west of Pittsburg, Pa. These have been 
used for pavements in loo cities and towns, two-thirds 
of which are in five of the eastern states, the rest being 
in three of the middle western states and four of the 
southern states. 

The materials are silica, alumina and iron, forming 
fire-clay, which is ground to powder and mixed with 
water in proper proportions and moulded into bevelled- 
edge vitrified paving bricks and blocks. 

Streets of Philadelphia, equal to over sixty miles 
length of thirty feet width, have been paved with these 
blocks, and it is stated by Wm. H. Brooks, chief of 
bureau of highways of Philadelphia, that some streets 
thus paved for over ten years have required no repairs 
and are now in good condition. 

CHARACTERISTICS. 

The material for moulding any paving brick must be 
of a peculiar character which will not melt and flow 
when exposed to an intense heat for a number of days, 
but will gradually fuse and form vitreous combinations 
throughout, while still retaining its form. 

The resulting brick must be a uniform block of 
dense texture, in w^iich the original stratification and 
granulation of the clay has been wholly lost by fusion 
which has stopped just short of melting the clay and 
forming glass. 

The clay while fusing must shrink equally through- 
out, thus causing the brick to be without any lamina- 
tions or any exterior vitrified crust difTering from the 

87 



CITY ROADS AND PAVEMENTS. 




S8 



ABRASION AND IMPACT TKST. 

interior. Such a brick will be incapable of absorbing 
any considerable amount of water, and will hence be 
unaffected by frost, and if formed of the best material 
properly treated will be tough, to withstand the blows 
of horses' toe-calks; hard to resist the abrasion of 
wheels, and strong to carry heavy loads: these being 
in the order of effectiveness of the destructive forces to 
be met. 

There is now little difficulty, with rigid inspection, 
of getting brick which will uniformly possess these 
qualities. 

QUALITIES OF PAVING BRICK. 

If the brick are uniform in character and are per- 
fectly formed of proper material which is thoroughly 
fuzed, they will be harder than glass and nearly as hard 
as quartz (being 6.5 on Mohs' scale), and will be tough 
enough to endure traffic. These qualities will be best 
determined by the followang described test: 

ABRASION AND IMPACT TEST. 

The standard test revised and adopted by the Na- 
tional Brick Manufacturers Association in 1900, pro- 
vides for the use of a machine having a rattling 
chamber twenty-eight inches in diameter and twenty 
inches in length, formed of two steel heads and four- 
teen steel staves set one-fourth inch apart to allow the 
escape of the chips and dust. This machine must be 
set to run uniformly at about thirty revolutions per 
minute for about sixty minutes, or for 1,800 revolutions 
by actual count of a cyclometer. Each separate charge 
of bricks to be tested must consist of bricks of one 

89 



CITY ROADS AND PAVEMENTS. 

kind, which must be perfectly clean and dry, and free 
from moisture : twelve paving bricks or nine paving 
blocks (so called because larger), are accurately weighed 
and constitute a charge, together with 300 pounds of 
cast iron in the form of blocks with rounded edges and 
corners : one-fourth in weight to be two and one-half 
inches square on end and four and one-half inches 
long, and three-fourths to be one and one-half-inch 
cubes. 

After 1800 revolutions, made as stated, the loss is 
determined by again weighing the brick: the limit of 
loss which is allowed varies in different specifications : 
the St. Louis specifications reject bricks when the 
tests show a loss of over thirty per cent of the original 
weight: Columbus, Ohio, puts the limit at twenty- 
seven and one-half per cent : many lots of bricks tested 
will lose less than tw^enty per cent. 

Such brick must be practically without pores, for 
a brick which can absorb water equal to more than two 
per cent of its dry weight, will probably fail to endure 
the rattler test. 

The absorption test is, therefore, not a useful one, 
and may mislead, and may safely be omitted. 

The tests by abrasion, and for absorption, and for 
crushing strength, are the most important of the numer- 
ous tests which are sometimes specified, and of the total 
value of all the tests, the abrasion test is variously con- 
sidered as varying from thirty per cent to seventy-five 
per cent of the whole. 

EXAMINATION OF BRICKS IN USE. 

The best and most useful test can, however, be made 
by visiting places where brick pavements have been in 

90 



EXAMINATION OF BRICKS IN USE. 

use for several years, and by examining tlic actual 
results of traffic upon well-known and standard makes 
of brick. 

For instance, Columbus, Ohio, has some eighty miles 
of brick pavement, varying in age from one to twelve 
years, in which twenty-six kinds of paving bricks and 
blocks have been used, with various kinds of fillers in 
the joints. Dayton, Oliio, has twelve miles of brick 
pavement, in which fourteen kinds of bricks and blocks 
have been used. 

Des Moines, Iowa, and Terre Haute, Indiana, have 
also large mileage, composed of great varieties of mate- 
rials, as have also Cleveland and Toledo, Ohio, Louis- 
ville, Ky., and Detroit, Michigan. 

A few days spent in such examination of pavements 
in actual use will make experiments unnecessary, and 
will enable the engineer wiio is planning new work to 
avoid poor bricks and to specify those kinds which can 
be depended upon to give good results. 

This method of natural selection is gradually forcing 
the poor grades of brick out of the market. 



91 



CITY ROADS AND PAVEMENTS. 




Mixing and placing- concrete base. 




Placing brick on sand cushion. 
BRICK PAVEMENT, PROSPECT STREET, CAMBRIDGE, MASS., iS 



92 



BUILDING BRICK PAVEMB:NT. 




Rolling' with two and one-half ton roller. 




Spreading Portland cement grout filler. 
BRICK PAVEMENT, PROSPECT STREET, CAMBRIDGE, .MASS., li 



93 



CITY ROADS AND PAVEMENTS. 
VARIOUS STYLES OF CONSTRUCTION. 

The table on page 84 is reproduced from the first 
edition as showing the actual practice in 1894 i^"^ the 
sixty-two cities there named, of which thirty-four then 
used one course of brick set on edge on a six-inch 
concrete base with a sand-cushion of one inch. 




Vitrified Br.cK- 
5ancl 
^ Concrete 

1- 



Brictt' pavement 



The table on page 100 shows a more general use of a 
concrete base in 1900 and 1901, and this is to be 
expected as showing a higher standard of work obtained 
at less cost. Broken stone forms a good base, especi- 
ally where it is covered with a layer of sand, with a 
course of second quality of brick, laid flat, as founda- 
tion for the surface-course of brick set on edge. 

Two courses of brick on sand have been used for 
seventeen miles of pavement in Topeka, Kansas, some 
of which has been in use for twelve years, and all of 
which is in fine condition in 1902. It is there pre- 
ferred as being less noisy than when laid upon a con- 
crete base, and being made from local brick has cost 
$1.25, or less, per square yard. 

A concrete base, for which details are given on page 
42, is, however, usually well worth the extra cost, and 
should be used in preference to any cheaper substitute ; 
especially for a city which has been educated to a cor- 
rect idea of what constitutes a good pavement. 

94 



SAND CUSHION. 



MODE OF CONSTRUCTION. 

The earth roadbed being sub-drained and rolled 
hard, as described for other pavements, should be 
formed with a regular crown of about one one-hundreth 
the width between curbs: the best amount of crown 
is an important matter discussed on page 30, and the 
following table is given to show the practice in 1900 
in twenty-seven cities having experience with brick 
pavements: 
Actual "Crown" of Brick Pavements as Built in 1900. 



CITY. 


State. 


Inches ]ier 
30 ft. width 
bet. curbs 


! 

CITY. 


State, 


Inches per 
30 ft. width 
bet. curbs. 


CITY. 


State. 


Inches ])er 
30 ft widtii 
bet curbs. 


Albany 

Atlanta 

Binghamton. . . 

Buffalo 

Columbus 

Dayton 

Detroit 

Elmira 

Erie 


N. Y.. 

Ga 

N. Y.. 
N. Y . . 
Ohio... 
Ohio... 
Mich . . 
N. Y.. 
Penn . . 


5 
5 
5 
5 
6 

4'f 
4-2 

6 


Fort Wayne. . 
Grand Rapids 
Harrisburg. . . 

Houston 

Jackson 

Joliet 

Mansfield 

Meridan 

j Milwaukie . . . 


Mich .. 
Mich .. 
Penn . . 
Texas.. 
Mich.. 

Ill 

Ohio... 
Conn . . 
Wis . . . 


4 
6 

5 
6 

4 
5 
6 
6 


New Orleans 

Peoria 

Sandusky 

Scranton 

Springfield . . . 

St. Paul 

Terre Haute . 

Toronto 

Troy 


La 

Ill 

Ohio... 
Penn . . 
Mass . . 
Minn . . 
Ind.... 
Ont ... 
N. Y.. 


5 
6 
6 

5 
3>^t0 7 

6 

7 
4 







BASE FOR BRICK PAVEMENT. 

This may be formed in either of the several ways 
mentioned on page 94, but should generally be four 
or six inches of concrete, as detailed on pages 42 to 56. 

SAND CUSHION. 

When ready to set the brick, the sand cushion is 
formed by spreading screened moist sand over the con- 
crete or other base: this is spread uniformly to the 
required depth of one and one-half to two and one-half 
inches, and smoothed and brought to the proper crown 
by wooden templates, traveling on wheels or shoes and 
resting on the top of the curbs on either side. Upon 
the true surface thus formed upon the sand, the brick 
are set on edge, the workmen standing only upon the 

95 



CITY ROADS AND PAVEMENTS. 

brick already laid, and placing the bricks in front of 
them in regular lines across the street; the brick in 
each course breaking joints with those in the next 
courses. The bricks are then rammed with a seventy- 
five pound rammer and rolled with a two and one-half- 
ton or a five-ton steam roller and settled firmly into the 
sand-bed. If the surface is then sprinkled and examined, 
soft brick can be detected and picked-out as being those 
which remain wet after the hard bricks have dried. 

JOINT FILLERS. 

No filler has yet been found that is perfect, and 
there are wide differences of opinion as to the best. 

Sand filler is cheap and allows the brick to be readily 
taken up and relaid, but it also allows the edges and 
corners of the bricks to chip and become rounded, and 
permits the bricks to settle at soft spots of subgrade. 

Portland Cement Gront of equal parts by bulk, of 
loose cement and fine sand, if properly made and 
applied, is better, and there are patented mixtures 
which are combinations of iron-slag and cement ground 
together, and which are equally good or better. Grout 
is irregular and worthless, unless the sand used is so 
fine as to remain in suspension, and such sand is not 
easy to obtain : grout should be poured into place, but 
is sometimes flushed broadly over the surface and swept 
into the joints. Grout makes it difficult to take up and 
relay the brick, but it can, if properly made and applied, 
perfectly protect their edges and corners and thus pre- 
serve a smooth surface, which is most desirable. 

For some reason which is not clear, the pavements 
with cement grout joints seem to be the most noisy. 

Paving Cement makes an elastic joint which in some 
cases is best, although it costs more than grout. The 

96 



JOINT FILLERS. 

usual composition consists of lOO })arts l^y wciglit of 
No. 4 coal-tar, til rcc parts residuum oil and twenty parts 
refined asphalt, kept and used at a temperature of 300° 
Fh., meantime carefully avoiding over-heating it. This 
hot mixture should be poured into the joints from a 
spout, or it may be poured upon the surface and swept 
in with steel wire brooms: a thin coating of sand 
should be at once spread over the pavement, and this 
will mix with the surplus pitch while still hot so that 
traffic will soon grind the whole from the surface and 
leave the bricks clean. 

Expansion. — The expansion of brick pavements 
during and after periods of extreme heat has been a 
frequent source of trouble, and many pavements have 
been thus heaved and broken ; in some cases by a quiet 
raising of the brick pavement until the arch thus formed 
was broken by its own weight or by traffic, as occurred 
at Niagara Falls in July, 1897, '^^'^^ "^^ Glens Falls in 
August, 1901: in other cases by sudden ruptures or 
explosions, as at Kansas City in July, 1901, where this 
occurred on seven streets and brick w^ere thrown ujd a 
foot or more. In nearly every case this peculiar result 
has occurred where the brick have been laid with cement 
joints, and where the cross-expansion has been pre- 
vented by rigid curbs ; or at the apex of grades from 
both ways, or at the top of a steep incline where the 
resulants of longitudinal expansion have been concen- 
trated at one place. 

Expansion-joints of one inch of coal-tar, or mastic, or 
bitumen or sand have been formed along the curbs on 
l3oth sides of the street and across the pavements from 
curb to curb at intervals of fifty feet: one city in 
centra] New^ York took special precautions of this kind 

97 



CITY ROADS AND PAVEMENTS. 

and yet has had more or less trouble every year. Other 
cities have taken no precautions and have no trouble. 
It remains to find a preventive. 



BRICK PAVEMENT FOR STEEP GRADES. 

Brick pavements are often used successfully on 
grades which are considered to be too steep for smooth 
asphalt, which may afford no foothold, or for macadam, 
which may be gullied by heavy rainfalls. It is often 
difficult to decide what pavement to use in such cases, 
and equally difficult to select from the various forms 
of vitrified bricks and the different ways of laying them, 
in order to secure the best results on steep slopes. 

The following table is given of the steepest grades 
of brick pavements, in actual use in 1900, in the cities 
named : the fact that such steep grades are in use, 
may not be taken as a reason for imitation, but may 
furnish conclusive reasons for avoidance. 

Maximum Grades of Brick Pavements — 1900. 



CITY. 


State. 


Grade 

in feet 

per 100 

feet. 


CITY. 


state. 


Grade 

in feet 

per 100 

feet. 


Albany 

Baltimore 

Columbus 

Des Moines . . . 
Erie 


N.Y... 

Md ... 
Ohio .. 
I owa . . 
Penn . . 

Ill 

Ohio .. 
Wis . . . 


9-3 

9 
1 1 

7 
6 

8 

8 


Nashville .... 
Parkersburg . . 

Peoria 

Philadelphia. . 
St. Joseph. . . . 

Toledo 

Troy 

Wheeling .... 


Tenn . . 
W. Va. 

Ill 

Penn . . 
Mo ... 
Ohio .. 
N.Y... 
W. Va. 


7 

8-4 
6 
10 


Joliet 

Mansfield 

Milwaukee .... 


5-6 

7 
8 



Cost. — The average cost of construction of brick 
pavement on concrete complete in 1894, ^^ot including 
curbing and extras, as shown by the table on page 84, 

98 



BRICK PAVEMENT FOR STEEP GRADES. 

was 32.21 per square yard, \arying from $1.56 at Alle- 
ghany, Pa., to $3.00 at Providence, R. I. 

In 1900, the cost is materially less, and the j^rices of 
several are given as a basis, being obtained from tlie 
"Engineering News" and the "Engineering Record,'' 
and from direct advices. 

On April 10, 1900, at Chillicothe, Ohio, offers were 
made by six bidders for pavement to be formed of either 
of seven different kinds of first-class paving bricks, using 
either of four different kinds of filler in the joints and 
naming a price for each ; six inches of concrete forming 
the foundation in each case. For the concrete base the 
prices ranged from twenty-eight to thirty-four cents, 
with an average of thirty-one cents per square yard. 

For the bricks laid in place, the prices ranged from 
seventy-seven to eighty-eight cents with an average of 
eighty-four cents per square yard. 

For the fillers, the prices per square yard ranged 
from an average of nine cents for cement to an average 
of sixteen cents for " No. 6 filler; " fifteen cents w^as bid 
and accepted for " Murphy grout,'' a patented mixture 
of powdered iron-slag and cement, which w^as used. 

For the complete pavement (not including excava- 
tion or curbs) the prices ranged from $1.24 to $1.38, 
with an average of $1.33 per square yard. 

On May 18, 1900, at Kewanee, Illinois, four bids were 
made for vitrified brick pavement on six inches of con- 
crete for w^hich the price for base, pavement and filler 
complete in place, ranged from $1.42 to $1.47, with an 
average of $1.45 per square yard. 

These and other prices are given in the table on 
page 100, in each case giving not only the minimum 
price, at which the work was done in each case, but 

99 



CITY ROADS AND PAVEMENTS. 



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GUARANTEE. 



also the liighest bid and tlie mean of all the bids, for 
use in preparing estimates of cost for similar works. 

GUARANTEE. 

Some cities now require that the price for a brick 
pavement shall include a guarantee that it will be kept 
in crood condition for a term of years and delivered in 
good condition at the expiration of this time. This 
term varies widely as indicated by the records of fifty- 
five cities of the United States which had, on January 
I St, 1899, 571 miles of brick pavements: of these, 
three require guarantee for one year; two for three 
years; thirt}'-two for five years ; one for six years ; one 
for seven years, and ten for ten years ; while eleven 
require no guarantee, some buying the brick and laying 
them by hired labor. The general tendency seems to 
be toward a five-year guarantee with a surety conipany 
bond. 



lOI 



CITY ROADS AND PAVEMENTS. 



^"^f*^- 
















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02 .. •• 



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I02 



AMERICAN SHEET-ASPHALT, ARTIFICIAL 
AND NATURAL. 



COMPARATIVE QUALITIES OF PAVEMENTS. 

Asphalt pavement ranks first in extent of use and in 
satisfactory qualities, being fairly durable, and cleaner 
and less noisy than brick. Vitrified brick, the latest 
and best types of wooden blocks and the more 
recent bituminous macadam, are its rivals for public 
favor. 

HISTORV OF ASPHALT PAVEMENTS. 

The original pavements were made in Paris in 1854 
and were formed of pulverized natural asphalt rock, 
mined at different places in France and Switzerland 
and Sicily. This rock is a natural combination of 
eighty-eight per cent of amorphous carbonate of lime, 
with twelve per cent of mineral tar or bitumen, form- 
ing a bituminous limestone, and is generally used for 
the comparatively small amount of asphalt pavements 
in European cities. 

A similar combination of sandstone and seven per 
cent to thirteen per cent by weight of bitumen is known 
as Kentucky sand-rock asphalt, and is used in some of 
the cities of the United States, having an advantage 
over the European bituminous limestone in being less 
slippery. 

103 



CITY ROADS AND PAVEMENTS. 

American Asphalt Mixture. — The artificial mixture 
1 of sand and asphalt was first used in Newark^ N. J., in 
1870, and on Fifth avenue in New York in 1873, 
, though its first extensive use was in Washington in 
1877. It has since been laid in vast quantities in about 
100 cities of the United States and is the best-known 
form of asphalt pavement. The proportions and 
methods have varied somewhat with the gain in accu- 
rate knowledge and with the judgment of the builders 
and with the local conditions. 

This artificial mixture, which forms an artificial bitu- 
minous sandstone, and also the Kentucky natural 
sand-rock, give better results than the European rock- 
asphalt, in that the sand which forms their greater 
part, affords a better foot-hold, so that fewer horses 
slip upon them and still fewer fall. Since 1883 Buffalo 
has paved with sheet-asphalt 2 1 7 miles of street having 
an average width of roadway of thirty feet, at a cost 
of over eleven million dollars, while Philadelphia has 
laid 235 miles; these cities alone having more than the 
combined mileage of all the European cities. The 
cities of the United States have in 1901, over 2,600 
miles of asphalt-paved streets, stated by Major 
- J. W. Howard, engineering editor of Municipal Journal 
and Engineer, to represent an investment of ninety-five 
million dollars. 

America}! Natural Sand-rock Asphalt, — To form 
this pavement, the quarried rock is ground and heated 
to 300° Ph., and taken to the work hot and spread 
directly upon the clean concrete base where it is then 
rolled and rammed into a compressed layer two inches 
thick, no "flux" and no "binder coat" being needed. 



104 



IIISTORN' OK ASrilAI.T 1'avp:ments. 

The sand-rock is sometimes used in coml)i nation 
with bituminous Hmestone in proportion varying from 
one and one to two and one. 




BARTON STREET, BUFFALO, N. Y., October 5, 1901. 

American Natural Sand-rock Asphalt, laid August, 1891. 

Pavement in perfect condition after ten and one-half years' use, during which time, 

there have been no repairs of damage due to wear or weather. 

There seems no good reason why the American 
bituminous rocks should not be so systematically laid 
as to give for the cities of the United States, pave- 
ments which are as good as, or are better than, those 
made for the cities of Europe, with their bituminous 
limestones. Buffalo has had about ten miles of Ameri- 
can sand-rock pavement since 1 890-1892; Frank V. E. 

105 



CITY ROADS AND PAVEMENTS. 

Bardol, M. Am. Soc. C. E., who has had charge as 
chief engineer of the department of pubhc works of ah 
the pavements of Buffalo for many years, states that 
these " rock-asphalt pavements have required practi- 
cally no repairs, although they have been laid from 
seven to eleven years." This pavement was laid with 
five-year guarantee on ten miles of fifty-one streets. 
The needed repairs made since the guarantees expired, 
have been confined to three miles of thirteen streets, 
nine to eleven years old, at a total cost of an average 
of three and eight-tenths cents per square yard of the 
total area of these streets. The accompanying view 
was taken in 1 901, of a street which has had no repairs 
since it was thus paved in 1891, and now shows good 
results. 

The average annual cost of repairs of this sand-rock 
asphalt pavement is put by Mr. Bardol at one cent per 
square yard, or one-third to one-fifth of the annual cost 
of repairs to artificial sheet-asphalt. Front street in 
San Francisco was paved with rock-asphalt in 1890 
and has had an exceptionally heavy traffic, but it is in 
perfect condition in 1902, having had no repairs during 
eleven years of use. 

In any northern city having either kind of sheet- 
asphalt pavement, there will usually be during each 
year two or three days or parts of days w^hen the asphalt 
will take a coating of ice upon which travel will be 
difficult unless sharp sand is strewn upon the roadway, 
but this is a small item in comparison with its many 
advantages. 

Appreciation of these advantages is shown in the 
Borough of Brooklyn (of whose department of high- 
ways, George W. Tillson, M. Am. Soc. C. E., who is a 

106 



VARIOUS COMPANIES. 



recognised authority on " Pavements and Paving Mate- 
rials," is chief engineer), where, during 1900, artificial 
sheet-asphalt was substituted for, or laid upon, other 
pavements on forty-three streets, equal in area to six- 
teen miles thirty feet wide. 

During the same year in the Borough of Manhattan, 
sheet-asphalt was also laid upon or in place of other 
pavements on sixty-four streets, equal in area to twelve 
miles thirty feet wide, and in the Borough of the Bronx, 
the same was done on fourteen streets, equal to four 
and one-half miles thirty feet wide. Of one group of 
twenty-four proposed paving works, seventeen were for 
replacing or covering old pavements with sheet-asphalt. 
See " Foundation " on page 1 13. 



VARIOUS COMPANIES. 

Since 1877 many different methods of construction 
ha\e been tried and a number of companies have been, 
and some are still, before the public as competitive 
builders of asphalt pavements. To do this successfully 
and with certainty requires skill and knowledge which 
can only be acquired by long and costly experience. 
A great city may well employ experts who can specify 
details and test materials and direct operations as has 
been and is done in Washington and New York, but 
cities of moderate size desiring to build a few blocks, or 
a few miles, of asphalt pavement, should not attempt to 
direct the details of construction and should not con- 
sider other offers than those made by some of the few 
great firms having the widest experience and possessing 

107 



CITY ROADS AND PAVEMENTS. 

the necessary exact knowledge of all of the many essen- 
tial details and having the best established reputations, 
who can safely assume all responsibility for materials 
and methods and can give an effective guarantee at 
reasonable cost, for a period of ten years ; five years 
not covering the critical time. 




COURT SQUARE, SPRINGFIELD, MASS. i>^oo 

Rock-asphalt laid in front of City Hall in 1897 and repaired in 1898. 

Soui^ccs 0/ Supply.— Th^YQ are many sources of sup- 
ply of different asphalts, each varying from the rest and 
each requiring its own treatment. Formerly that from 
Lake Trinidad was assumed to excel all others for 
forming the American asphalt mixture ; but large de- 
posits were discovered in 1899 in northern Venezuela in 
addition to Bermudez Lake in the Department of Sucre, 
which alone is eight times the size of Lake Trinidad. 
There is also in Venezuela another newly found deposit 
of asphalt near the Gulf of Pavia in the Orinoco delta, 
and another in the state of Jujuy in Argentina. 

108 



ARTI Fin AL SHEET-ASri I A I .T. 

The American supplies of Kentucky sand-rock and 
of California sand-asphalt are very large and are free 
from international complications. 

MATERIALS AND METHODS; AMERICAN ARTIFICIAL SIIELT- 

ASPHALT PAVEMENT. 

Asphalt. — The full details of the materials and of the 
methods of construction are omitted here, but those 
which are given are based upon the practice during 
1900 in the city of Washington, where closest atten- 
tion is given to the subject by the engineer commis- 
sioner of the District of Columbia, aided by Prof. A. 
W. Dow, whose expert ability is widely known. Trini- 
dad and Bermudez asphalts are used with results which 
appear to be equally good. They are " refined " by 
simply evaporating the water which occurs with them 
in their crude state, and which forms about one-third 
of the Trinidad Lake asphalt. This refined asphalt 
must be softened to be useful as a paving cement, and 
for this effect there is used a flux, which is generally a 
heavy mineral oil or petroleum residuum. 

Asphalt cement is the result of mixing eighty-one to 
eighty-seven parts, by weight, of refined asphaltum, 
with nineteen to thirteen parts of flux. This forms 
the matrix cf the asphalt pavement, constituting nine 
and one-half to twelve and eight-tenths per cent, or an 
average of nine and seven-tenths per cent by weight of 
the asphalt mixture forming the wearing surface. 

Asphalt cement of a softer consistency is formed by 
mixing seventy-two to seventy-eight parts of refined 
asphaltum with twenty-two to twenty-eight parts of 
flux. This forms the matrix of the "binder," or about 
five per cent of its total weight, or about eight per cent 
of its bulk. 

109 



CITY ROADS AND PAVEMENTS. 

Skill and care are required to vary the amount of 
flux, so as to produce the uniform results necessary for 
a reliable pavement. 

Asphalt Mixture. — The "asphalt mixture" above 
referred to is formed by mixing about nine and seven- 
tenths parts by weight of asphalt cement with ninety- 
one and three-tenths parts of hot sand and stone-dust 
and limestone dust: the asphalt cement varying dur- 
ing 1900 from a minimum of nine and five-tenths to a 
maximum of twelve and eight-tenths per cent. This 
limited amount of asphalt cement is less than the actual 
voids in the sand, but the " mixture " becomes too plas- 
tic, and forms waves when rolled, if the attempt is made 
to use enough asphalt cement to wholly fill the voids 
which are probably equal to at least five per cent after 
it is rolled and finished. 

Saiid. — The careful and exact testing and propor- 
tioning of the sands and the stone-dust and limestone 
dust are a special feature of later practice. Formerly 
it was only required that sand should be clean and free 
from objectionable matter, but since 1894 it has been 
recognized that there are many varieties of sand, no 
two deposits being alike and no deposit being uniform. 
Samples are now taken constantly and are heated to a 
proper degree of dryness, and then passed over a series 
of screens to determine the relative proportions of each 
size. 

The composition of each of the various sands which 
are available being thus learned by tests, two or more 
kinds are combined in certain proportions, using great 
care from day to day to obtain a perfectly uniform mix- 
ture having a minimum of voids. These voids are in 
turn filled, as nearly as possible, by adding a varying 

1 10 



MATERIALS AND MHTMODS, KTC. 

proportion — averaging about one-tenth of the weiglit 
of the sand — of finely powdered siHcaor fine stone-dust. 

Limestone dust was formerly used exclusively for 
this purpose, but during recent years powdered silica 
or powdered mineral of any kind has been used instead 
and has been thought to be better in some ways : but the 
latest evidence in 1900 is said by Prof. A. \\\ Dow, to 
show that powdered limestone acts differently in some 
way and that the toughest and best asphalt is produced 
when, in addition to the stone-dust, powdered limestone 
is also used. 

The sand resulting from these admixtures had the 
following proportions as the average mesh compo- 
sition of the sands used during 1900. The voids were 
the least possible and were probably not more than 
twenty-five per cent nor less than twenty per cent when 
the sand was shaken and packed as closely as possible. 

Percentages of the sand retained on sieves as follows: 

10 meshes per linear inch none. 

20 meshes per hnear inch 6.;^ per cent, 

40 meshes per linear inch 30.1 per cent. 

60 meshes per linear inch 23.7 per cent. 

80 meshes per linear inch 15.6 ])er cent. 

100 meshes per linear inch 7.8 per cent, 

passing 100 meshes per linear inch 16.5 per cent. 



1 00.0 ])er cent. 

This accurate proportioning of the sand and of the 
stone-dust to fill its voids was found necessary in order 
to prevent the uncertainties caused by the variation in 
character of the sand in different localities — it proving 
cheaper to go to this expense and trouble than to make 
good the failures which formerly occurred when all 
care had apparently been used in making and })lacing 



1 1 1 



CITY ROADS AND PAVEMENTS. 

the ordinary mixture. This has been done since 1894 
by the best equipped companies, who have learned the 
necessity, and the details, from experience and who 
are therefore able to guarantee their work in a w^ay 
which was not formerly possible. 

Crushed Stone for '* Binder T — Crushed stone to 
form the " binder " consists of any tough, hard rock 
and is the total product of the crusher passing through 
a one and one-quarter inch screen, with some of the 
dust removed and with the coarse screenings of the 
sand added. 

Ninety-five parts of this by weight are mixed while 
hot with about fiYQ parts of the softer asphalt cement 
before described. 

The amount of asphalt cement varies with the char- 
acter of the stone, the hot asphalt cement being added 
in the mixer until all faces of each fragment are coated^ 
but avoiding any excess of asphalt which might tend 
to fill the voids between the fragments of stone. 



FORMATION OF THE PAVEMENT. 

Foundation, — If the street has never been paved, 
the base of the proposed asphalt pavement is made of 
hydraulic cement concrete four inches or six inches 
thick. The usual practice is here shown and in the 
table on page 56. 



Con creTfe 




Asphalt Pavemenr 
112 



FORMATION OF THE PAVEMENT. 

Much of the sheet-asphalt laid in the great cities has 
been put directly upon old pavements of cobbles or of 
stone blocks, of which the depressions maybe filled with 
hot crushed stone sprinkled with hot asphaltic cement^ 
or which may be merely re-set at points of subsidence 
to restore the regular form, but which are usually re-set 
at three inches lower grade and with the proper crown 
in order to make room for the "binder" and the 
" wearing surface " of asphalt, without having to raise 
the manholes, car-tracks and curbs. The lower part of 
Seventh Avenue, New York, was thus treated during 
1 90 1. The joints between the stones of the old pave- 
ment should be three-fourths of an inch wide and 
should be brushed and cleared for at least an inch in 
depth to afford a firm hold for the " binder." 

In some instances, stone blocks for a base have been 
re-laid flat to give a lower grade, but this is not good 
practice and has given poor results unless there is a 
concrete base beneath the old blocks, as was the case 
in New York on Broadway below Forty-second street 
to Canal street which was thus treated in 1901. 

Brick pavements built in 1887 have been used as 
base for sheet-asphalt for many miles of streets in 
Columbus, .Ohio. 

Old macadam roads have often been successfully 
used as foundation for sheet-asphalt, and this may work 
well until cuts are made for sewer and water and gas 
connections when it will be difficult to restore the 
pavement. 

Binder. — The mixture of stone and asphalt which 
has been described at page 112, is brought hot from 
the mixer and is spread over the clean and dry base, 
using rakes to give it a regular depth of two inches, 

113 



CITY ROADS AND PAVEMENTS. 

where it is at once compressed to one and one-half 
inches with a steam roller which may be slightly sprayed 
with water to prevent adhesion. 

When completed, this "binder" must be firm so that 
fragments are not displaced by the passage of con- 
struction teams, but the surface must be open and 
" honey-combed " so that it may give a good hold for 
the " wearing surface " which should follow at once if 
possible and certainly on the same day. All trafhc 
must be kept off during whole progress of work. 

If the fragments of binder are not firm, or if its voids 
are filled by excess of asphalt cement, such portions 
must be removed and replaced by perfect material. 

Asphalt work of all kinds should stop during rain^ 
or snow-fall, or freezing weather. 

Wearing Surface. — This is formed of the " asphalt 
mixture" which has been described on page no, and 
must be brought hot from the mixer and should reach 
the work with a temperature of about 280° Fh. : the 
surface of the " binder " should be swept perfectly clean 
to receive it, and it should be spread with hot rakes to a 
uniform depth of two and one half inches of the loose 
material, taking care to loosen that coming from near 
the bottom of the cart which must be scraped clean 
after every load. The loose layer is spread two and one 
half inches deep to form a one and one half inch finished 
surface, or three and one-third inches to form a two- 
inch surface, which latter is much the better for heavy 
traffic. 

Rolling the Wearing Surface. — The " asphalt mix- 
ture " is then rolled with a cold 1200-pound hand roller^ 
the surface of which is constantly wiped with a piece 
of oily cotton-waste to prevent adhesion. 

114 



FORMATION OF TIIF I'AVKMFNT. 

After this rolling which is done quickly, tlie surface 
of the asphalt is covered with finely ground dry mineral 
dust (generally using dry liydraullc cement), wliich is 
swept over the surface to give it tlie soft gray color 
which is desired and to j^revent the adhesion of the 
five-ton finishing roller with which the " wearing sur- 
face " is rolled until compressed to one and one half 
inches or two inches in thickness and until the surface 
is perfect. Cities are about equally divided as to which 
of these thicknesses is used, as indicated in table on 
page 56. 

This rolling will usually occupy about one hour on 
sixty feet length of pavement thirty feet wide. 

The entire manipulation of the material, and espe- 
cially its spreading and rolling, require skill and care 
not only for the general features here described but 
also for many other important details which are neces- 
sary to secure good results. 



TT5 



CITY ROADS AND PA.VEMENTS. 







CARROLL STREET, BROOKLYN, NEW YORK, 1900. 
Before covering cobble pavement with sheet-asphalt in 1900. 



116 



SUKKKT-AS I'll ALT rAVKMKNT. 




CARROLL STREET, BROOKLYN, NEW YORK, 1900. 
After paving with Trinidad sheet-asphalt in 1900. 



117 



CITY ROADS AND PAVEMENTS. 
GRADE AND CROWN. 

The actual steepest grades existing in various cities 
are shown in the accompanying table, in order that 
those having doubts in any extreme case may examine 
some of these grades and observe the results. 



Actual Grades of Sheet-Asphalt. 



CITY. 


State. 


Ft. per loo 
feet. 


CITY. 


State. 


Ft. per loo 
feet. 


Buffalo 

Erie 


N. Y.... 
Penn. ... 

Mich 

Conn 

Ohio.... 
N. Y.... 

Neb 

Ill 


5-1 
5 

7 

5 

5-75 

5 
8 

7-2 


Pittsburg 

Salt Lake City. 
San Francisco . 

St. Joseph 

Scranton 

Syracuse 

Toledo 

Troy 


Penn . .. 
Utah.... 

Cal 

Mo 

Penn. .. 
N. Y. .. 
Ohio.... 
N. Y. .. 


17 

5 
i6 

8 

13 

7 
5 
7-5 


Grand Rapids.. 

Hartford 

Marion 

New York 

Omaha 

Peoria. 





The crown used in various cities on level streets is 
shown in the same way; it being borne in mind that 
the least crown which will shed water makes the best 
road for those who use it. See " Crown of Pavement," 
at page 30. 



Actual " Crown " of Sheet-Asphalt. 



CITY. 


State. 


Inches ]ier 
30 ft width 
bet curbs 


CITY. 


State. 


Inches per 
30 ft. width 
bet. curbs. 


CITY. 


State. 


Inches per 
30ft width 
bet. curbs. 


Albany 

Atlanta 

Bine;hamton.. . 

Buffalo 

Charleston 

Columbus 

Dayton 

Detroit 

Elmira 

Erie 


N. Y.. 

Ga 

N. Y.. 
N. Y . . 
S. C. . . 
Ohio... 
Ohio . . 
Mich . . 
N Y.. 
Penn . . 


5 
5 
5 
5 
4 
6 

4^ 
->% 
4^ 
6 


Fort Wayne. . 
Grand Rapids 
Harrisburg. . . 

Hartford 

Houston. 

Jackson 

Joliet 

Mansfield 

Meridan 

Milwaukie . . . 


Mich . . 
Mich . . 
Penn . . 
Conn . . 
Texas.. 
Mich . . 

Ill 

Ohio... 
Conn . . 
Wis . . . 


4 

6 

\)i 
6 

h4 

II 


Muncie 

New Orleans 

Peoria 

Sandusky .... 

Scranton 

Springfield . . . 

St. Paid 

Terre Haute . 

Toronto 

Troy 


Ind.... 

La 

Ill 

Ohio . . 
Penn . . 
Mass .. 
Minn . . 
Ind.... 
Ont ... 
N. Y.. 


12 

5 

6 

6 

5 

3>^ 

5^ 

7 

7 

5^ 







118 



RIGID RAIL-BASE. 
RAITAVAV TRACKS IN ASPHALT-PAVED STREETS. 

When railway tracks are laid in streets paved with 
asphalt, there is wide variation in the manner of con- 
struction next the rails : of fifty-two cities having this 
condition to meet, all have, until recently, put some 
other material than asphalt next to the rails : fourteen 
using granite blocks, six using stone blocks, and four- 
teen using vitrified brick. 

The best practice in Buffalo, Rochester, Pittsburg 
and elsewhere, is to use ninety-pound rails with nine- 
inch or ten-inch webs welded in continuous lengths, and 
placed on twelve-inch concrete base to insure rigidity: 
the asphalt surface being then laid in contact with 
the rails. See page 40. 

The practice in Rochester since 1899 and in Pitts- 
burg in 1 90 1 has been to first place the heavy steel rails 
accurately on line and grade with temporary supports, 
and then to form the twelve-inch concrete base beneath 
the rails ; ramming and tamping the concrete until it 
rises against the rail-base and gives it a perfect bearing 
at all points without having to use w^edges. 

COST OF SIIEET-ASPIIALT. 

This varies widely with local conditions and with 
the competition and can best be seen by reference to 
the tables here and at page 56, showing rates with and 
without concrete base and curbs. 



119 



CITY ROADS AND PAVEMENTS. 
PRICES FOR SHEET-ASPHALT PAVEMENT, 

NOT INCLUDING BASE OR CURBS OR EXTRA WORK. 



DATE. 


Oct. 


I, 


1900. 


Jan. 


I, 


1901. 


Sept. 


26, 


1900. 


Oct. 


I, 


1900. 


Sept. 


> 


1900. 



PLACE. 



Guar- 
antee. 



Albany, N. Y 10 yrs 

Cedar Rapids, Iowa j 

Cincinnati, Ohio 5 yrs 

Owensboro, K y ] 

San Antonio, Texas j 10 yrs. 



No. of 
Bids. 



Price per Sq. Yd. 



Max. 


Aver. 


Min. 


2.17 


$1.91 


$1.34 


2.02 


i-«3 


1.69 


2.31 


2.21 


1.97 


2.09 


1-93 


1.80 


2.00 


1.56 


1.40 



INCLUDING 6 INCHES OF CONCRETE AS BASE. 



DATE. 


PLACE. 


Guar- 
antee. 


No. of 
Bids. 

5 
2 


Price per Sq. Yd. 




Max. 


Aver. 


Min. 


Aug. 7, 1900. 
March 3, 1901 . 
Aug. I, 1900. 

, 1899. 

March 4, 1901 . 
— , 1899. 

— , 1899. 

— , 1899. 

, 1898. 

— 1899- 

— , 1899. 

, 1899. 

Dec. 31, 1900. 
Sept. 3, 1900. 


Aurora, 111 


5 yrs. 

10 yrs. 
10 yrs. 
10 yrs. 
10 yrs. 

5 yrs. 

5 yrs. 

5 yrs. 

5 yrs. 

5 yrs. 

10 yrs. ^ 

5 yrs. 

ID yrs. 

5 yrs. 


$1.97 
2.27 

2.35 


$1.88 
2.34 


$r.8i 


Baltimore, Md 


2.17 

2.33 
1.89 
2.00 

1.95 
2.13 

1.95 

1.70 

1.70 

1-53 
2.62 


Cortland, N. Y... 


Fort Wayne, Ind 

Houston, Texas 

Joliet, 111 


3 


2.90 


2.42 


Milwaukie, Wis 

New Orleans, La 

Oswego, N. Y 




2.23 










Peoria, 111 








Rochester, N. Y 

Sandusky, Ohio 

St. Paul, Minn 


includ- 
ing 
excav. 


>2.26 


2.04 








Toledo, Ohio 




2.65 


2 27 


2.10 







Note. — Mainly from the columns of the Engineering News and of the Engineering Record. 

GUARANTEE. 

It is now usual to require that the price paid for a 
sheet-asphalt pavement shall include a guarantee that 
it will be kept in good condition for a term of years and 
delivered in good condition at the expiration of this 
time: this term varies as is indicated by the records 
of forty cities of the United States which had, on Jan- 
uary ist, 1900, 757 miles of sheet-asphalt pavement: 
of these, twenty require guarantee for five years and 
twenty require a guarantee for ten years. Ten of the 
latter have formerly required five years, but now require 



120 



GUARANTEE. 

ten, showing a tcMidency toward a ten year guarantee. 
Maintenance guarantees for long terms were required 
for the sheet-asphalt pavements of Fifth avenue and of 
Broadway, New York. Asphalt was laid in 1S96-7 on 
Fifth avenue with fifteen years' guarantee at the follow- 
ing prices per square yard, including new concrete base : 
from Ninth street to Fifty-ninth street, the cost was 
^4.35 : from Fifty-ninth street to Eightieth street, $4.00: 
from Eightieth street to Ninetieth street, $3.29: these 
different rates indicating the expected effects of traffic 
on the cost of maintenance. 

Asphalt was laid in 1900 on Broadway, with fifteen 
years' guarantee, from Fifty-eighth street to Fourteenth 
street, upon new concrete base to Forty-second street 
and upon the old stone blocks relaid flat upon two 
inches of sand over the old six-inch to eight-inch con- 
crete base below Forty-second street. The cost was 
$5.37 per square yard. 

Asphalt was extended in 1901 down Broadway to 
Canal street, and cost $6.31 per square yard. This in- 
cluded fifty-nine cents for relaying the old blocks fiat 
upon the old concrete base and also ten years' main- 
tenance. This should include strewing sharp sand 
when the pavement is slippery, as on Fifth avenue and 
on all wood-block and asphalt pavements abroad. 

The average cost of a guarantee in Buffalo is put by 
F. V. E. Bardol, M. Am. Soc. C. E. (see page 56), at 
three cents per square yard for the first five years and 
fifteen cents for the second five years or eighteen cents 
for ten years. 

The probable cost of a guarantee for the third five 
years would in some cases equal the cost of an entire 
renewal of the surface. 

121 



CITY ROADS AND PAVEMENTS. 




122 



SHEET-ASrUALT PAVEMENT. 



f^^ 




^:/ 





123 



CITY ROADS AND PAVEMENTS. 
CAUSES OF FAILURE OF SHEET-ASPHALT. 

A reasonable amount of traffic tends to prolong the 
life of a good sheet-asphalt pavement. When a pave- 
ment beghis to fail, the causes are probably to be found 
in about the following order: 

First. — Defective foundation, which has settled and 
caused the hollows in which pools of water have stood 
upon the surface of the asphalt until it has become 
disintegrated. 

Second. — Wearing surface too soft, or excess of 
asphalt in binder, or dirt on surface of binder, either of 
which may allow " wearing surface " to creep under 
traffic and to form waves or rolls, in which the sheet of 
asphalt mixture is thickened, alternating with hollows 
where it has become thin. 

Third. — Patches where the pavement has been torn 
up for sewer and water connections and not well restored. 

Fourth. — Surface cracks, which sometimes appear in 
cold weather as a result of excessive contraction of the 
surface, and which sometimes close and re-unite in 
warm w^eather under the combined effects of warmth 
and of passing wheels. 

Fifth. — Excessive traffic which has worn off the sur- 
face. This is the least common. 

Sixth. — Lack of traffic, allowing the asphalt to 
become spongy. The latter cause usually shows its 
effects at the sides of the roadway next the curbs, 
where there is least passage of wheels. The process 
of failure may then be as follows : 

The material composing the sheet of asphalt expands 
slightly with the sun's heat, as all other substances do; 
but unlike most other substances, it does not of itself 
at once return to its original thickness when the heat 

124 



CAUSES OF FAILURE OF SIIEET-ASrilAI.T. 

is lost, because the asplialt becomes rigid as it cools, 
and unless compressed by force, tends to remain in its 
expanded form. In the center of the roadway, where 
most of the wheels pass, the asphalt is at once re-com- 
pressed, but at the sides this is not done so promptly, 
with the result that there is a tendency to become 
somewhat porous or spongy where there is little traffic. 
When at last the asphalt has thus actually become 
porous, water can permeate it, and this soakage of 
water is helped by the fact that the surface-drainage is 
toward the sides, where the material is most likely to 
absorb some of it. Having thus absorbed ever so little 
moisture, of course both heat and frost have increased 




JEFFERSON AVENUE, HROOKEYN, iqoo. 
Destriictive effects of gas leaks on sheet-asphalt pavement. 



CITY ROADS AND PAVEMENTS. 

effects upon the material, and ultimately it shows signs 
of disintegration. 

Seventh. — When a failure of asphalt is so complete 
as to include several of these features, it will usually 
be found that the pavement was built by some local 
paving company, wdthout previous experience, whose 
bid should not have been considered and whose work 
and guarantee proved to be equally worthless. 

EightJi. — Disintegration of surface may also result 
from defects in the mixture of asphaltum and flux or 
from the laying of the pavement during freezing 
weather; disintegration is frequently caused, espe- 
cially in Brooklyn, New^ York and Kansas City, by the 
escape of illuminating gas from leaky mains. The 
hydrocarbons which are now used in these cities to 
enrich and cheapen illuminating gas, are solvents of 
asphaltum ; leaks of this destructive and tenuous gas 
from the underlying main pipes are the direct cause of 
failures like those shown in the accompanying photo- 
graph of Jefferson avenue, Brooklyn, taken in 1900. 

Disintegration of asphalt is also caused by the spill- 
ing of kerosene by careless vendors, and by the drop- 
ping of oil from the axle-boxes of street-cars. 

Bonfires are sometimes built on asphalt pavements 
with destructive effect, and this was done in one case 
with a misdirected desire to celebrate the completion 
of the pavement w^hich it injured. Most of these causes 
of failure are preventable by proper selection of the 
builders or by proper care of the finished work. 

There are many cases — among them Oswego, N. Y., 
as shown on the frontispiece — where no defects of any 
kind have appeared during and after five years' use of 
the pavement. 

126 



BLOCK ASPHALT PAVEMENT. 

Asphalt blocks are used in many cities of the United 
States, there being in 1900 the equivalent of ninety-five 
miles of pavements, thirty feet wide. During 1900, 
twenty-one streets, equal in area to three miles, thirty feet 
wide, were thus paved in the Borough of Manhattan, 
equaling twenty-five per cent of the sheet asphalt laid in 
1900. 

Washington, in July, 1900, had twenty-two miles of 
such pavement, as compared with 141 miles of sheet- 
asphalt. The asphalt blocks laid in 1900 were formed of 
thirteen per cent asphaltic cement, ten per cent limestone 
dust and seventy-seven per cent crushed gneiss, and 
cost $1.77 per square yard laid, not including base. 

The character of asphalt blocks has been much im- 
proved during recent years and the proportions are now 
usually about as above stated, except that crushed diabase 
trap or basalt is generally used and with better results. 
The materials are heated to 300° Fh. and are mixed 
in a rotary mixer until all the faces of every particle of 
the crushed stone are perfectly coated with the mixture 
of asphaltic cement and limestone dust. The product 
is then put in moulds twelve inches long, four inches 
or five inches wide and three inches or four inches deep 
and subjected to a pressure of two to two and one-half 
tons per square inch and then slowly cooled in water. 

This is done in a factory where the best results may 
be obtained and the blocks are then shipped to their 
destination, where they can be laid, like brick, in cold 
weather, if necessary, by unskilled labor. 

This last feature constitutes their chief advantage 
over sheet asphalt. The blocks are laid in close con- 

127 



CITY ROADS AND PAVEMENTS. 

tact, sometimes on gravel covered with sand, though a 
concrete base is best, upon which the blocks are some- 
times bedded in one inch of Portland cement mortar. 
Asphalt blocks made as above described, have worn 
well, but there are few cases where sheet-asphalt is not 
preferable. The following table shows the prices of 
recent pavements of this kind : 

Prices for Block-asphalt Pavement, Four Inches Thick, Including Six 
Inches of Concrete as Base and Filler in Joints. 



Date. 


CITY. 


State. 


Guar- 
antee. 


No. ot 

bids. 


Price per Sq. Yard. 


Max. 


Aver. 


Min. 


Mar. II, 1 90 1 
Mar. 13, 1901 

Mar. II, 1901 

Sept. 3, 1900 
Feb. 18, 1901 


Annapolis . 
Chillicolhe. 

Pontiac 

Toledo 

Toledo 


Md.. 

Ohio. 

Mich. 

Ohio. 
Ohio- 


5 yi-s. 

5 ys. 
5 yrs. 

5 yrs. 


2 

^ On 6 in.| 
1 gravel. J 

18 
3 


$2 85 

3 25 

2 55 


$2 80 

1 17 

2 32 
2 45 


$2 75 

1 07 

2 40 

1 95 

2 25* 



* (On sand base, seventeen cents less; on stone base, three cents less.) 

A cheaper modification of block-asphalt, known as 
the Leuba pavement, has been in successful use in 
Neuchatel, Switzerland, since 1898, and consists of 
blocks eight and three-fourth inches long, four and one- 
half inches wide, and four inches to four and one-half 
inches thick, but with the lower three-quarters of each 
block made of hydraulic Portland cement and clean, 
sharp sand in proportions of about one to four : this 
concrete base being covered with a w^earing surface 
one and one-fourth to one and one-half inches thick of 
compressed natural rock-asphalt: the tw^o materials 
being joined under heavy pressure, and the blocks 
being laid with cement joints on a concrete base. 



128 



BLOCK-ASPHALT PAVEMENT. 





BLOCK ASPHALT PAVE^IEXT, NINETY-SIXTH ST., NEW YORK, 1900. 
Looking- west from Third avenue to Park avenue. Paved in 1900. 



129 



CITY ROADS AND PAVEMENTS. 



List of Cities Having Both Sheet-Asphalt and Brick 

Pavements. 

Miles of each with preference. 



city. 



Albany 

Atlanta 

Baltimore 

Binghamton .. 

Boston 

Buffalo , 

Cleveland 

Columbus 

Dayton , 

Detroit , 

Elmira 

Erie 

Fort Wayne .. 
Grand Rapids 
Harrisburg . . . 

Houston 

Jackson 

Joliett 

Mansfield 

Marion 

Milwaukee . . . 

Minneapolis.. 
New Haven .. 
New Orleans . 

Peoria 

Philadelphia.. 

Rochester 

Sandusky .... 

Scran ton 

Springfield . .. 
St. Joseph . .. 

St. Paul 

Terra Haute. . 

Toronto , 

Toledo 

Troy 

Washington .. 



Total 



State. 



N. Y. 
Ga ... 
Md .. 
N. Y. 
Mass . 
N. Y. 
Ohio . 
Ohio 
Ohio 
Mich . 
N. Y 
Penn 
Mich 
Mich 
Penn 
Texas 
Mich 
111.... 
Ohio.. 
Ohio.. 

Wis ... 

Minn 
Conn 
La ... 

Ill 

Penn 
N. Y 
Ohio 
Penn 
Mass 
Mo .. 
Minn 
Ind .. 
Ont .. 
Ohio 
N. Y 
D. C. 



Sheet- 
Asphalt, 
Jan. 1, 1900. 



9 

2 

7 
5 

14 
217 

9 
15 
17 
22 



miles 

miles 

miles 

miles 

miles 

miles 

miles 

miles 

miles 

miles 

0.8 mile 

II miles 

7 miles 

6 miles 

3.4 miles 
4 miles 
0.4 mile 
3 miles 
I mile 

1.5 miles 

ID miles 



13 

3-5 
23 
8 

235 

43 
I 

12 

0-3 

9 
13 

3-5 
24 

21.6 

4 
141 



miles 

miles 

miles 

miles 

miles 

miles 

mile 

miles 

mile 

miles 

miles 

miles 

miles 

miles 

miles 

miles 



Brick. 
Jan. I, 18 



16 
2 
I 
2 
I 

7 
66 

74 
12 

24 
o. 
6 

ID 

4 
o. 

7 
2. 

3 

15 

6 



miles 

miles 

mile 

miles 

mile 

miles 

miles 

miles 

miles 

miles 

mile 

miles 

miles 

miles 

mile 

miles 

miles 

miles 

miles 

miles 



2 miles 



5 

1-5 
59 
22 
120 

7 

6.5 

2 

1-5 

7 

3 

4-5 
8 

42 

8-5 
I 



miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
miles 
mile 



920 miles 560 miles II 



Preference. 



As- 
phalt. 



Brick. 



On over 
4 per 
cent 

grades. 



13 



Not stated. 



13 



(Compiled by Willis Fletcher Brown, consulting engineer of Toledo, Ohio.) 



130 



BITUMINOUS MACADAM, OR BITULITHIC 

PAVEMENT. 



During 1901, a practically new form of pavement 
with the above name has attracted much attention and 
has come into use at widely separate places : its favor- 
able discussion in the Engineering News of January 
30, 1902, and in the Engineering Record of the same 
date, has confirmed many in the opinion that this was 
a new factor in the solution of the paving problem 
although the test of time is yet to be applied. 

The former bituminous or "tar" pavements have 
usually been formed of sand the fine grains of which 
have no other stability or structural strength than is 
derived from the matrix of asphalt or of coal-tar in 
which they are embedded : or they have consisted of 
tarred fragments of stone with twenty per cent or more 
of void spaces, generally placed without systematic 
heating and mixing. 

The new pavement is formed of trap rock, or other 
tough rock, crushed and screened to fragments varying 
in size from two inches down to the dust, and com- 
bined in such proportion of sizes that the final spaces 
between the fragments of rock do not exceed ten per 
cent. This means that the fragments must be in actual 
and firm contact with each other and that the addition 
of ten or twelve per cent, by bulk, of bituminous com- 



BITULITHIC PAVEMENT. 




Adams Street, Lowell, Mass. 
Rolling and coating the base. 




Temple Street, Cambridge, Mass. 
Spreading and rolling the wearing surface. 

BITUMINOUS MACADAM, 1901. 
132 



DETAILS. 

pound will fill the remaining voids and make a solid 
and impervious mass. 

When this is accomplished, the result must be a 
pavement which water cannot penetrate and which 
should support the passage of traffic without abrasion 
of the fragments upon each other and without the 
bituminous filler being exposed to action of the 
weather. 

It is obvious that the success of the pavement will 
be dependent upon the care which is used in the selec- 
tion of the materials and the skill and thoroughness 
shown in combining and placing them, and that these 
features are as important as for an asphalt pavement. 

BASE. 

The base for the new pavement is prepared as for a 
macadam road; the earth road-bed being graded, 
drained, formed and rolled, and then covered with a 
layer of the best stone available w^hich is crushed and 
screened to two inches and larger and is rolled with a 
fifteen ton steam roller into a compact layer four inches 
thick. This stone base is then sprinkled with a thin 
hot bituminous mixture and then covered with a coat- 
ing of thicker hot bituminous mixture which binds the 
surface of the base and prepares it to receive the next 
layer w^hich is spread on top of it. 

TOP. 

The " wearing surface " is then spread w^iile hot, and 
is rolled and compressed to a final thickness of two 
inches: this "wearing surface" is formed of the best 
available rock, preferably trap rock, which has been 
crushed and screened to retaii^i all less than two inches : 

^33 



CITY ROADS AND PAVEMENTS. 

this is then dried and heated in rotary drums and then 
screened in rotary screens which separate it into the 
various sizes from two inches down to dust. These 
sizes are then proportioned, and some sand added if 
necessary, in such ratio as shall give a minimum of 
voids not exceeding ten per cent : this low ratio of 
voids being only possible by careful study. 

The heated stone is then run into a mechanical mixer 
at a temperature not exceeding 300° Fh., together 
with hot bituminous cement (which may consist of 
asphalt), in sufficient quantity to fill all voids and to 
coat all faces of all particles of stone and dust and 
sand, and also to provide a slight surplus of " filler." 
When thoroughly mixed by about 1 50 revolutions of 
the mixer, it is hauled to place on the street and is 
spread and rolled in the same manner as asphalt, but 
using a fifteen to twenty-ton steam roller to compress 
it and to crowd the bitumen into all the voids, forcing 
out all air-bubbles and making the surface as dense as 
possible. 

Upon this surface, filling its irregularities and mak- 
ing it sticky, there is then poured and rubbed a coating 
of quick-drying bituminous cement, heated to 250° Fh. 
and over this is spread about a quarter-inch layer of 
small stone chips which are rolled and forced into 
the sticky coating forming a final wearing surface: 
these chips being larger in proportion as the grade is 
steeper, so that a good footing is given for horses on 
steep grades. 

COST. 

During 1901 streets have been thus paved by vari- 
ous city departments, under expert advice and super- 

134 



OPINIONS. 

vision, at New Bedford, Holyoke, Cambridge, Lowell 
and Brockton, Massachusetts, and at Salem, N. J., and 
Pawtucket, R. I., and Charleston, S. C; and the cost 
has ranged from $1.25 at Holyoke, Brockton and 
Lowell to $1.50 per square yard at Salem, or about 
double the cost of ordinary macadam of the same 
thickness. 

The city engineers and oflficials of these cities have 
spoken so favorably of it that a number of cities are to 
follow their example during 1902 at varying costs from 
$1.80 to $2.75 per square yard, which in each case in- 
cludes guarantee for five years. 

Among these are Taunton, Mass., Norwich, N. Y., 
Charleston, S. C, Yonkers, N. Y., and three miles of 
" State Road " leading south from Cleveland, Ohio, 
which last is to cost $1.40 per square yard: also, two 
and one-fourth miles of Seventh Avenue, New York 
city, from iioth street to 155th street, which, if done, 
will cost about $2.75 per square yard: the five year 
guarantee in this case being important, as the trafific is 
heavy. 

WIDTH AND GRADE. 

The pavement usually extends from curb to curb, 
the widest built being forty feet at Salem, N. J., and 
the narrowest being sixteen feet proposed near Cleve- 
land, Ohio. 

The steepest grades are eight feet to twelve feet per 
100 on Harvey street, Pawtucket, R. L, and ten feet to 
fifteen feet per 100 proposed at Yonkers, N. Y, 

OPINIONS. 

This new pavement has been in actual use only 
since January, 1901, but the opinions expressed by 

135 



CITY ROADS AND PAVEMENTS. 




MAPLE STREET, HOLYOKE, MASS.,1901. 
Before and after paving with Bituminous Macadam. 



136 



OPINIONS. 

skilled road-builders, who have examined it critically, 
are favorable as to its durability and \'alue. 

In addition to the officials of the various cities named, 
many city engineers and street superintendents ha\e 
examined these pavements during and after comple- 
tion, and intend to build similar ones in their various 
localities, it being found that the winter and spring of 
1902 have left these in good condition. 

Among these are the president of the Massachusetts 
highway association, C. A. Brown of Cambridge ; the 
vice-president of the Massachusetts highway asso- 
ciation, R. A. Jones, of Waltham ; Prof. A. W. Dow of 
Washington, D. C, who is quoted by the Municipal 
Journal as expressing the opinion, based upon what he 
knew of it, that this pavement exceeded in good quali- 
ties any other pavement that he had seen laid. Chas. W. 
Ross of Newton, former State highway commissioner 
of Massachusetts, commended it to the convention of 
supervisors of New York State at their annual meeting 
at Albany on January 28, 1902, saying that its use 
would prevent the storm-washing of macadam streets 
on steep grades and would have saved Newton from 
damages amounting to $20,000 which were caused by 
a single shower in July, 1901. 

With such weighty opinions from unbiased experts, 
it is evident that this pavement is a factor to be con- 
sidered in future projects for city streets. 



137 



BROKEN-STONE ROADS. 



In the recent wide discussion of " Good Roads," mac- 
adamizing or some more or less similar arrangement of 
small fragments of broken or crushed stone, is most 
often spoken of, and the general reader who has given 
no special attention to the subject further than to read 
the many articles which appear in papers and maga- 
zines is most likely to conclude that some such con- 
struction suits all conditions and localities, though it is 
really best suited and most used for highways outside 
of the business parts of cities. 

Within the past eight years, there has been an in- 
creased use of broken stone roads for residence-streets 
of cities, resulting from the examples of good work given 
by the governments of various states in building high- 
ways by state aid outside of corporate limits, and thus 
familiarizing city ofificials with the methods by which 
the best roads of this kind can be built and maintained. 

This is especially manifest in the cities of Massa- 
chusetts, where over 200 miles of macadamized streets 
have been built since 1894 i^"^ the cities of Brookline, 
Cambridge, the Newtons, Medford and Springfield, as 
well as 240 miles in Boston. Also in many cities of 
New York State, especially in a section of Buffalo, near 
Delaware Park. The city of Greater New York leads 
in this as in all things, the five Boroughs having on 

138 



EXTENT OF BROKEN-STONE ROADS. 

January ist, 1901, the following stated miles of mac- 
adam streets and boulevards. Manhattan, eighty-two 
miles; The Bronx, ninety-one miles; Brooklyn, eighty- 
two miles; Richmond (Staten Island), 183 miles; 
Queens (on Long Island), 388 miles ; Central Park, 
nine and a half miles (all telford, 1869 to 1878); Pros- 
pect Park, six and a half miles ; Greenwood, twenty 
miles; or a total of 862 miles of broken-stone roads 
within the city, practically all but forty- five miles built 
since 1894. 

The building of rural roads by state aid was begun 
in 1893 by the State of New Jersey, which pays one- 
third of the cost of construction ; followed in 1894 ^Y 
the State of Massachusetts, which pays three-fourths of 
the cost, and by Connecticut in 1895, ^vhich pays two- 
thirds to three-fourths of the cost, and by New York 
State in 1898, which pays one-half of the cost: the bal- 
ance in each case being paid by the towns or counties. 
In Maryland, the state aids the counties by making 
their surveys and plans and directing the improvements. 

Under these systems, the roads most considered and 
most built have been of the two principal types of con- 
struction known as the macadam and the telford, though 
many miles of gravel roads have also been built and 
many miles of highways in each state named have been 
merely improved by forming and draining the natural 
materials as found, with the idea that this work may be 
later continued by putting broken stone upon the road- 
ways thus begun. 

ROCK FOR ROADS. 

Trap. — The three states first named are fortunate 
ii"! having many formations of good rock for road con- 

139 



CITY ROADS AND PAVEMENTS. 

struction, while New York State is mainly limited for 
the best grade of rock to the diabase-trap or dolorite 
formation lying on the Hudson River in Rockland 
county, just north of Nyack and opposite to Sing Sing 
or Ossining. 

This lies ten miles north of the limit of the proposed 
Palisades Reservation, is more accessible by canal boat 
and by railroad than any part of the Pahsades and con- 
tains enough material of the best grade to macadamize 
all the roads in the state. The many quarries of New 
Jersey and Connecticut are also available for roads in 
New York as well as in those states. There was also 
discovered in 1901 a large isolated mass or "plug" of 
trap rock, near Schuylerville, N. Y., about twenty miles 
north of Albany, lying close beside the Champlain 
canal and the railroads. Other similar formations have 
been found in Clinton county by the State Geologist, 
Professor F. J. H. Merrill. Trap rock is the best for 
road construction, in that it has no true cleavage and 
breaks irregularly with toothed surfaces, and is tough 
and does not easily grind into dust and mud. Its spe- 
cific gravity is great, so that its dust does not blow so 
readily as that of limestone. 

Porphyry is ranked next, but it is not common and 
the supply in New York State is limited to Lake 
Champlain. 

Quartzite, and siliceous qiiartzite are more common 
and in some cases make very good road-material. 

Granite of some varieties is a good road-material, in 
proportion as it contains a small amount of mica and 
of quartz, and is not weathered. 

The same is true of gneiss and of syenite, which are 
granitic and of which large and accessible formations 

140 



ROCK FOR ROADS. 

exist at Little Falls, on both sides of the Mohawk ri\ei\ 
where there are unlimited quantities, close to the Erie 
canal and the railroads. Throughout Westchester 
county, N. Y., there are many and varying ledges of 
gneiss, some of which are tough and good, but many 
of them carry an excess of mica and of quartz and of 
feldspar, and crumble readily, especially when weath- 
ered, and are unsuited to road-making. 

Limestone usually binds well and readily and, if 
unusually hard, makes a good road. Well-known 
examples of the best limestones, which have been and 
are much-used for road-making, are the Tompkins' 
Cove stone and tlie Clinton Point stone, quarried on 
the Hudson, forty miles and seventy miles from New 
York, and the Bethlehem stone, near Albany, N. Y., 
and the Jammerthal flint-limestone, quarried in the 
suburbs of Buffalo, N. Y. 

Some of the other limestones, which also bind readily 
and have been used for roads, contain an excess of 
lime and crush under heavy trailRc, and form a light 
and impalpable dust, wdiich is most objectionable to 
residents as well as to drivers. This dust is only 
avoided by keeping these roads constantly wet, entail- 
ing an expense for sprinkling w^hich proves to be more 
costly than to use a better stone which does not form 
such dust. 

Soft limestones form a good low^er course to be cov- 
ered by a harder wearing-surface or top course. The 
cementing action, so called, of limestone, is purely 
mechanical, but it serves to firmly bed the fragments 
and to prevent them from rubbing and W'Caring against 
each other. The use ot limestone screenings is dis- 
cussed at page i6o, under ''Quality of Screenings." 

141 



CITY ROADS AND PAVEMENTS. 





<*•, ,««*'^ 



Mr: . 










feg: 


ii^i 








1 






-i 


^ 


1 




^pr/,. 


^ 


"^H 


^C^Sa 


■Sf»^I|^^f'l ' 






?^^^^^^H|^H^^^^HH 


M 


^^ptte^ ,xp- 






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Sandstone or "bluestone" road, built m Ulster county, N. Y., 
by state engineer E. A. Bond, M. Am. Soc. C. E., in 1900. 



142 



COBBLE-STONES. 

Sandstone is only suited for use where better rock 
cannot be readily obtained, and then only for tlie base 
course where it should be covered by a wearing sur- 
face of trap or other tough rock. An exception to this 
must be made in favor of the ''blue-stones" of Ulster 
county, and the five adjacent counties of eastern New 
York, which are true sandstone and are peculiarly 
tough. The Ulster county stone binds readily with its 
own screenings, and has been used to form the whole 
material of good six-inch macadam roads, which stand 
well under moderate traffic and are here shown. 

Various Kinds of Rock. — Broken stone roads can 
be well made with various rocks, requiring varied 
treatment to suit the conditions. The many rocks and 
the details for their successful use, can nowhere be 
better studied than in New York State, which probably 
contains as great a variety of geologic formations as 
any other equal area in the world. 

IMPORTANCE OF UNIFORMITV. 

In the selection of material to be crushed for road 
metal, uniformity in character is of the first importance; 
material which is uniformly of a second grade being 
preferable to a mixture of better and worse. Such a 
mixing of fragments of hard and soft rocks results in 
quickly crushing the softer pieces and then exposing 
the harder pieces to excessive shocks from passing 
wheels. 

COBBLE-STONES. 

Rounded cobble-stones gathered from tlie fields and 
lake shores, make a very poor wearing sui"face for a 
road, whatever their composition. 

143 



CITY ROADS AND PAVEMENTS. 

Being worn by action of water or ice into rounded 
forms, all of the fragments crushed from them have at 
least one curved or water-worn face. These curved 
and polished faces prevent the adjacent fragments 
from coming to a solid bearing in a road. They will 
always be likely to rock or slide under passing loads, 
and thus loosen all the fragments which touch them. 

Further, these rounded cobble-stones which were 
strewed broadcast over parts of the country during the 
glacial period, came from the most widely different 
localities in the northern part of the continent and 
include all varieties and degrees of hardness. 

Granite, syenite, quartz, limestone, flint and slate 
were found to make up one-tenth of a mass of them, of 
which the remaining nine-tenths were sandstone, of 
which at least one-half were so disintegrated or weather- 
worn — so " rotten," as the workmen call them — as to 
be worthless for any purpose: for road-surface metal 
they are worse than worthless, as their only effect is to 
destroy the good material with which they chance to be 
mixed. 

Crushed cobble-stones may be selected to form the 
lower or base course, if nothing better is available, by 
rejecting all which are inferior and by selecting, to be 
crushed and screened, only the hardest and best. 



144 



TESTS OF ROAD MKTAI. 




145 



TESTS OF ROCK FOR ROAD-MAKING. 



The various rocks available for road-making are 
compared as to their relative endurance, by subjecting 
similar sets of samples of each kind to similar abrasion 
in machines like that here shown, which was devised 
by Deval in 1878. Each set of samples consists of 
eleven pounds, or five kilograms, of roughly cubical 
selected fragments, none smaller in any way than one 
and one-quarter inches, nor larger than two and one- 
half inches. These are cleaned, washed, dried and 
accurately weighed, and enclosed in one of the cylinders 
and tightly sealed. Similar sets of samples are put in 
each cylinder and the whole machine is then slowly 
revolved at the rate of 2,000 revolutions per hour for 
five hours, or until a cyclometer registers 10,000 
revolutions. 

The fine dust worn from each set of samples is then 
saved for cementation tests, and the fragments are 
washed, dried and again weighed : comparison of the 
percentage of loss of each set indicates the relative 
endurance which is also to be seen by examining the 
fragments of rocks before and after testing. 

The department of civil engineering of Columbia 
University has a most complete equipment with which 
Prof. Wm. H. Burr, M.Am. Soc. C. E. has caused to be 
made many useful tests of road materials, and Harvard 

146 



TESTS OP^ ROCK FOR ROAI)-M AKIXG. 

is similarly equipped : the testing laboratory of the 
college of civil engineering of Cornell Uni\ersity, 
directed by Prof. E. A. Fuertes, M. Am. Soc. C. E., is 
also fully equipped and makes many tests of stone and 
bricks for pavements, as does the highway division of 
the Maryland geological survey at Johns Hopkins 
University, directed by Harry Fielding Reid by whose 
courtesy the plates of machines and samples are here 
given. Records of similar tests of various rocks have 
been made and published by the highway commission 
of Massachusetts, by the highway division of the 
geological survey of Maryland, by the U. S. ofKice of 
road inquiries at Washington, by the State geolo- 
gist of New York and by the State engineer of New 
York and these records are useful guides in selecting 
stone for road-construction. 



H7 



CITY ROADS AND PAVEMENTS. 





MARBLE. 




HARD LIMESTONE. 




DL\BASE TRAP ROCK. 



ROCK FRAGMENTS BEFORE AND AFTER ABRASION TEST. 
Two-thirds natural size. 

HIGHWAY DIVISIOX, MAKYLAND GEOLOGICAL SURVEY. 



148 



TESTS OF ROCK FOR ROAD-MAKING. 

The following table shows the results of loo tests of 
the six kinds of rock most used in Massachusetts and 
New York: 



KIND. 



Diabase trap 
Limestone . . 
Granite . . . . 
Quartzite . . . 

Gneiss 

Sandstone . . 





Per cent 


OF Loss BY i 


Number of 
tests. 








1 




Max. 


Min. 


35 


4.31 


1.40 


24 


6.68 


2.33 


10 


4-30 


2.23 


7 


5-9° 


1.97 


12 


6-57 


1-73 


12 


6.69 


1. 71 



Mean. 



2.28 

4.34 

3-52 

?>-(^?> 
4.01 



(The last item includes Medina Sandstone at a. 29 and Ulster " Bluestone " at 3.71.) 



Several local rocks are sometimes available of which 
there may have been no tests, but experience will 
usually enable a selection to be readily made of the one 
which will give the best results. The rock which will 
bind the most readily will probably be the least durable, 
and it may be more economical to make a long haul of 
a good rock than to use one which is near at hand, but 
which will soon need renewal. 



149 



THE MACADAM AND THE TELFORD SYSTEMS. 



About a century ago Macadam preached and prac- 
ticed a gospel of good roads for England with an 
effectiveness which our leagues of to-day can only hope 
to imitate in the United States. 

England had long had roads of broken stone, and 
the use of this material was not peculiar to Macadam's 
method ; but he was the first to establish rules of con- 
struction which were generally accepted, and under 
them were built 25,000 miles of road which formed a 
network all over England; so that his name has come 
to be associated with broken stone as a road material, 
although Telford, who came twenty-five years later, 
used the same material but in a different manner. In 
Macadam's talk to committees of Parliament and to his 
workmen, he always enforced the idea that the whole 
secret of making a good road was to keep its earth-bed 
dry ; that the ground was the real road and must bear 
the weight of the stones, as well as of the traffic, and 
that the subsoil, however bad, would carry any weight 
if made dry by drainage and kept dry by an impervious 
covering. 

In this requirement Telford and all skillful road 
makers fully agree. 

This dry roadbed. Macadam covered with a layer of 
road metal of a finished thickness of five to ten inches 

150 




be M 



C 3 

o « 



•^ ^ 



3 « 

_. *^ 

1- - 

O X 



J 



i^HliilHBHHHaBaB^ 



CITY ROADS AND PAVEMENTS. 

(varying with the weight of traffic), composed of small 
angular fragments of the hardest and toughest rock, 
broken to a uniform size, as nearly as possible to one 
and one-half inch cubes, or six ounces each in weight. 
No dimension larger than two inches was allowed, and 
any piece too large for a workman to put in his mouth 
was to be broken again. 

In the matter of Telford's foundation for a broken 
stone road and Macadam's omission of it, there are 
wide differences of opinion and of practice: French 
and English engineers generally omitting the telford 
foundation and many American engineers seeming to 
tend toward the same practice, or to limiting the use of 
telford foundations to those portions of roads where the 
earth subgrade is not firm. 

The latter practice is best because where the sub- 
grade is firm, the telford base serves as an anvil upon 
which the shocks of traffic break the fragments which 
form the surface. Where the sub-grade is dry and well 
drained, the telford base has the effect to more quickly 
remove the moisture which helps the binder to bed and 
to hold the surface-fragments. Sprinkling is done in 
dry weather to supply this moisture and without it the 
road " ravels." This raveling will occur sooner on a 
dry section of telford road than on a similar section of 
a macadam road, but this difference is not so important 
when the roadway is a city street which is sprinkled 
and shaded. When the sub-grade tends to being wet, 
the telford base is desirable as a foundation, and costs, 
when local stone is at hand, thirty to thirty-five cents 
per square yard. 



152 



TELFORD ROADWAYS. 
COST. 

As to the relative cost of the two methods, it is usual 
that telford is somewhat more expensive, but the fol- 
lowing does not so show. 

At Somerville, N. J., on October 22d, 1900, proposals 
were received for two miles of eight-inch macadam and 
for six miles of ten-inch telford and macadam, each of 
trap rock, each twelve feet in width, and each including 
about 2,000 cubic yards of excavation per mile : the 
prices were in cents per square yard: 

Average at 
Max. Min. 14 bids. 

For eight-inch macadam roadway complete. . 8;^ 50 62 
For ten-inch telford roadway complete 8;^ 50 66 

For the stone roadways only, not including grading 
and drainage, for eight roads built in New Jersey, dur- 
ing 1900, the average costs were: 

For four six-inch macadam roads, fifty-three cents 
per square yard ; for four eight-inch telford roads, fifty- 
one cents per square yard. 

During 1901, as stated in the report of Henry I. 
Budd, commissioner, nine eight-inch macadam roads 
averaged seventy-seven cents per square yard and three 
eight-inch telford roads averaged sixty-one cents per 
square yard. 

TELFORD ROADWAYS. 

The general requirements for construction of telford 
roadways are similar in the different states with the 
exceptions which will be named: the earth roadbed 
or subgrade, is excavated and carefully rolled and 
formed as for a macadam road, conforming to the })ro- 
posed cross-sections and twelve inches below the estab- 
lished grade of the finished road. 

153 



CITY ROADS AND PAVEMENTS. 



On this subgrade are then placed by hand the stones 
forming the telford foundation, which may vary in size 
as shown below: each stone must be set vertically 
upon its broadest edge, lengthwise across the road and 
forming courses and breaking joints with the next 
course, so as to form a close and firm pavement. The 
stones are then bound by inserting and driving stones 
of proper size and shape to wedge the stones in their 
proper position. All projecting points are then broken 
with a sledge or hammer so that no projections shall 
be within four inches of the finished grade-line. The 
telford foundation is then rolled with a steam roller of 
ten or more tons weight, until all stones are firmly 
bedded and none move under the roller. All depres- 
sions are then filled with stone chips not larger than 
two and one-half inches, and the whole left true and 
even and four inches below the line of finished grade 
and cross-section. 

A good workman will average about twenty minutes 
in setting a square yard of this telford foundation, 
which may be formed of any kind of quarried rock 
which is most available : cobble-stones are not suitable. 

The practice in 1901 in the states named is here 
shown : 

Sizes of Stone for Telford Foundation, in Inches. 



STATE. 


Depth, as 

SET ON 
EDGE. 


Width, as 

SET. 


Length, 
set across 

ROAD. 


Remarks 




Max. 


Mm. 


Max. 

4 

10 

10 
1 
10 


Min. 


Max. 


Min. 




j 
New Tersev. 

Mass 

Conn 


8 
6 

8 
8 


8 

5 
8 
6 


4 

6 

4 


10 

15 


6 

8 
6 


Alternate end-stones 

double length. 
Two inches gravel rolled 

on sub-grade as base. 
Macadam covering 

formed in one layer. 
Used only on unstable 
ground as foundation 
for macadam. 


New York . . 



154 



CITV ROADS AM) I'AVIIMKNTS. 

The re(juir(jincnts for formin^^ the four inches or six 
iiiclu'S of l)rokcn stone roadway upon this telford 
foundation are tlie same as for re^^ular macadani. 

()f the inilea;_;"e of l)r()ken-slone roads ])uilt ])y State 
aid (hu"in^ Kjoo, telford foundation was used for one- 
sixth in New Jersey, one-seventh in Coiuiecticut, one 
tliii'ty-ei^lith in Massachusetts and none in New York. 
During- 1901, New Jersey used tlie same ])ro|)ortion as 
in 1900. 

NEKI) OF r>INI)i;K Willi UROKKN S'l'ONK. 

Macadam required that tlie layer of regular frag- 
ments sliould l)e s]:)read on the earth roadbed, to l^e con- 
sohdated ])y the wlieels of ]:)assin^ vehicles, without tlie 
aid of any fine material or of " binder" of any sort. 

This recjuirement was impracticable and j^robal^ly 
could not be enforced, and exj:)erience has shown that 
it is not desirable that it should be enforced. 

Such fragments, loosely jailed or spread, have about 
forty-six to forty-ei^ht ])er cent of void sj)aces, and will 
pack by i-ollin^ to about three-fourths of their thickness 
when loose. 

The consohdation of ])erfectly clean, re^^ular, angular 
fragments of trap rock, free from screening's or binder 
of any sort, was thoroughly tried by Mr. Grant in Cen- 
tral park, New York city, in i(S6o. A ])iece of road 
covered with Macadam's ideal road metal, free from 
binder, was rolled for several days, until the fragments 
were worn and rounded, without hrm consolidation 
being effected, and this experience has been recently 
repeated elsewhere. 

Road material which can be ])acked without binder 
must be of a ])()or (pialit}', which will supply itself 

^5(> 



MODKS Ol' I'SK OK lUNDI.K. 

with l)iiuk'r 1)\- ruadih' griiuliiig" iiUo dii^t and small 
j)ic'(X's. 

'rc'lford's sNstrin dilkTcd radicalh' in that he first 
covered the earth roadbed with a i-oiigh pax'ement ol 
firmly set stones, and that the wearing" la\er of broken 
fragments xaried in si/e, and that a hinder of fine 
material was spread over the surface to help in its 
consolidation. 

Moi)i:s oi" i;si'; of r,i\i)i:K. 

This is one of the most important features of mac- 
adam road construction, and the different modes which 
produce sucx'cssful results on State roads are therefore 
gi\'en in detail. 

/// Jiiigland there are now various methods in use, 
l)ut as a general thing Macadam's method of using 
])erfectly clean fragments of hand-broken rock is not 
now followed. The commonest ])ractice seems to be 
to use tw'enty-five ])er cent of binder called "hoggin," 
consisting of a mixture of loam, coarse sand and small 
graxel. This "hoggin" being worked into the la\('!- 
of broken stone by flooding the roadwa)' with water. 

Jji pyance, where the greatest care is given to road 
construction and maintenaiKX', twent}'-ri\'e ])er (x-nt ol 
sand is generall\' used with the broken rock as a binder. 
This is washed to fill the \'oids between the fragments 
of rock, with a final addition of ehalky dirt and watei- 
to fill the voids in the sand. See (piotation on |)age 
I 69. 

In llic United States, where little or no stone is now 
l)roken by hand, ex])erience has satisfied most /Xmeri- 
ean engineers that the roads wear better and have less 
dust and fewer loose stones if binder is put upon the 

'57 



CITY ROADS AND PAVEMENTS. 

consolidated layer of crushed stone to fill the spaces 
which remain after rolling, and this binder is usually the 
stone dust and the small fragments from the crusher 
which pass through the circular holes, half an inch in 
diameter, of a revolving cylindrical screen. The use 
of binder is the same whether the construction is tel- 
ford or macadam. 

In Nczu Jersey, after the lower course of broken 
stone has been rolled until compacted, trap rock screen- 
ings one-half inch to dust, free from loam or clay, are 
spread over the lower course in a uniform layer and 
the course is again rolled until the stones cease to sink 
or creep in front of the roller; water being applied in 
advance of the roller if required. The same treatment 
is given to the top course. This is then covered with 
a mixture in equal parts of three-fourths inch crushed 
trap and of half inch trap screenings, properly mixed 
and spread in sufificient thickness to make a smooth and 
uniform surface which is rolled until hard. Sandy loam 
is used with good results upon some New Jersey roads. 

Ill Connecticut^ after each of the two courses has 
been rolled until solid and iim, dry trap rock screen- 
ings not larger than one-half inch are scattered over 
the surface so as to fill all interstices and the roller is 
then run over the road to shake in the dust. 

The sprinkler is then used to wash in the screenings 
and then more screenings are added, rolled dry and 
then sprinkled, and these processes are repeated for 
each course until all interstices are completely filled. 
When the top course has thus been made firm and 
smooth, it is then covered with one inch of screenings 
to form a wearing surface. 

158 



MODES OF USE OF lUNDFR. 

/;/ Massachusetts, tlic lower course is tliorouglily 
compacted by rolling, but no screenings or filler are 
spread or used upon it. After the top course has also 
been thoroughly compaced by rolling, screenings of the 
same kind of stone which forms the top course are laid 
on in just sufficient quantity to cover the stone and are 
then watered and rolled until the mud flushes to the 
surface. The screenings are not treated as a part of 
the wearing surface but are used simply to hold the 
larger stone in place, using as little as possible. 

In N'ciu Yoi'k, the screenings used as filler are usu- 
ally limestone when the road-material is brought from 
a distance, but are often the product of the local crushed 
stone when local rock is fit for use ; sometimes local 
rock and its screenings are used for the lower course 
only, but when possible they are used for the top also. 
In some cases when local granitic rocks are used, the 
screenings for the top course are caused to bind prop- 
erly by mixing an equal amount of limestone screen- 
ings with granitic screenings. In other cases good 
results have been obtained by mixing an equal amount 
of clean sand with the granitic screenings. Trap and 
granite and quartzite screenings are limited to a maxi- 
mum of one-half inch, but those of softer rocks are lim- 
ited to three-quarter inch. After the first course of 
broken stone has been rolled until the stones do not 
creep or weave ahead of the roller, the dry screenings 
are spread uniformly to a depth of one-half inch and are 
then rolled dry and are swept with brooms of steel or 
rattan until the screenings disappear among the stones, 
when the process is repeated until no more will go in 
while dry: the surface is then wet with a sprinkler 
(unless the subgrade is of clay), using water freely until 

159 



CITY ROADS AND PAVEMENTS. 

all voids are filled, leaving the surface of the stones 
free from screenings. See page 175. 

The top course is then spread and rolled and treated 
in the same manner in sections of about 300 feet length, 
water being freely used and the rolling continued until 
a grout has been formed of the stone-dust and water 
and until a wave of this grout is pushed before the 
wheels of the roller. After this effect is produced, 
screenings are spread and rolled, leaving three-eighths 
of an inch depth for a wearing surface. After forty- 
eight hours, or when the surface has dried, the road 
is again rolled and sprinkled and then opened to traf- 
fic, being meantime sprinkled daily for thirty days. 

QUALITY OF SCREENINGS. 

Trap. — The best "binder" for the top course, all 
things considered, is probably a mixture of three parts 
of trap-rock dust and screenings, with two parts of 
smooth sand not too coarse. In addition to its tough- 
ness, trap-rock dust has the advantage as compared 
with limestone dust, of having a greater specific gravity, 
so that it does not blow readily. If this mixture fails 
to " bind," or if it " ravels " afterward, a different grade 
of sand may help it, or a small addition of one-fourth 
or less of cementitious limestone screenings, like that 
from Tompkins Cove, will certainly make it bind. 

Limestone. — Some kinds of limestone screenings 
make a sticky paste, which is very bad, and it is 
important to select carefully and to study the effects 
closely. Cementitious limestone dust and screenings 
" bind " broken stone better than will any other mate- 
rial, and many experienced road-makers consider that 
limestone of some kind is necessary to make a good 

160 



QUALITY OF SCREENINGS. 

road; but the facts remain as detailed on pages 157, 
158 that vast extents of perfect roads have been built 
and maintained without it, both in this country and 
abroad, during years past as well as recently. 

Granite. — The screenings crushed from granitic rocks 
and from gneiss have in some cases been successfully 
used to bind the crushed rock from which they were 
screened. In other cases, during 1901, perfect results 
have been obtained from granite screenings which 
would not " bind " by mixing with them an equal quan- 
tity of carefully-chosen local sand. 

Qtcantity of Screeni7igs. — The actual quantity of 
screenings required to thus bind the crushed stone and 
to fill the voids, varies somewhat with the character 
of the rock and with the degree to which it is crushed 
and ground together by the roller: with trap rock, 
w^hich is not crushed by rolling, the loose yardage of 
screenings needed to fill the voids will equal thirty- 
three per cent of the loose yardage of the crushed rock 
measured in the bin : with some gneiss, or with soft 
limestone, or with sandstone, the screenings may not 
exceed twenty-five per cent of the loose yardage of the 
crushed stone measured in the bin. A fair average 
with the various rocks will be thirty per cent, which 
will be ample if the screenings are not wasted. 



161 



MAXIMUM GRADES FOR MACADAM ROADS. 



There is a wide difference between theory and prac- 
tice in the matter of maximum grades on which broken- 
stone roads may be built and maintained. Grades of 
less than five feet per loo feet are not only better for 
the traveling public, but can also be built and main- 
tained at less cost, because it is more diflficult to roll 
macadam on steeper grades, and because the fragments 
are loosened by horses toe-calks and are washed by 
rain-fall. 

In the construction by state aid in the states already 
named, the roads are necessarily outside of corporate 
limits and are usually old highways on which the 
steeper grade can be reduced by cutting the tops of the 
hills and by filling the valleys, or in extreme cases by 
changing the line of the road and making a new loca- 
tion around a hill instead of going over its top. In 
this way, the maximum grade on state work in Massa- 
chusetts and in New York is nominally five feet per 
hundred because this is considered to be the most 
economical for the convenience of travel and for the 
cost of maintenance. In both these states, grades as 
steep as six and one-fourth feet per hundred are found 
necessary in some cases. 



162 




ml' ■ 

.ti-..., > 



* f/f 



\ 



■VVl 



.5^ 




X _, 



H 



^ a; 
c 






CITY ROADS AND PAVEMENTS. 



In New Jersey, among the roads built in 1900 are 
the following upon which the grades are steep: 



NAME OF ROAD. 


Construction. 


Thickness, 
inches. 


Width of 
macadam, ft. 


Max. grade, 

ft. and tenths 

per 100 ft. 


East Passaic avenue 

Budd's Lake road 

Passaic ave. (E. bank 

Passaic river) 

Patterson and Hamburg 

Turnpike 

Mendham-Bernardville. . 


Telford .... 
Macadam. . . 

Telford .... 

Macndam .. 
Macadam . . 


8 
6 

10 

t 


16 
10 to 16 

20 

16 
12 


7-5 
7-5 

8.86 

9 
10.75 



Upon city streets, however, it is often difficult to 
make any radical change in the grade, and always im- 
possible to avoid hills by change of location, so that 
grades which are steeper than these are sometimes 
used, and with surprisingly good results. 

The city of Newton, Massachusetts, comprises fifteen 
villages in an area of twenty square miles, containing 
some sixty miles of the finest macadam roads, which 
are built and maintained in perfect order by commis- 
sioner Chas. W. Ross, formerly member of the state 
highway commission. Among these finely kept roads 
are the following : 



NAME. 


Length of steep 
grade. 


Grades in 


Village. 


Street. 


feet per loo 
feet. 


West Newton .... 
West Newton .... 

Newtonville 

Newtonville 


Chestnut street 

Mt. Vernon street . . 
Highland avenue. . . 
Otis street 


1000 feet 
J 000 feet 
1000 feet 
1200 feet 
700 feet 
600 feet 
1500 feet 
1000 feet 


9 feet 

9 feet 

10 feet 

10 feet 


West Newton .... 
West Newton .... 
Newton 


Prospect street 

Putnam street 

Bellevue avenue. . . . 
Newtonville avenue. 


10 feet 

10 feet 

9 feet 

12 feet 


Newtonville 



164 



STEEP CxRADES FOR MACADAM ROADS. 

All streets having grades steeper than fi\'e feet j^er 
I GO have paved gutters three feet or more in widtli for 
which concrete is preferred to cobbles as being more 
durable, being free from weeds, and giving the best flow. 

The city of Waltham, Mass., has fine macadam streets 
with the following described steep grades built since 

1895: 



NAME OF STREET. 


Length of 
steep grade. 


Width of mac- 
adam in ft. 


Max. grade, 

in feet 
per 100 feet. 


Main street 

Newton street 


I COO feet 
500 feet 
700 feet 
400 feet 
400 feet 


40 feet 
20 feet 
20 feet 
20 feet 
20 feet 


7 
8 


Plympton street 

Bellevue street 


9 
12 


Plympton street 


13 





These streets have paved gutters three and one-half 
feet wide and the cost of their maintenance after the 
first year is stated by superintendent R. A.Jones to be 
about one cent per square yard per year. 

Clinton, Mass., has the following described macadam 
streets with steep grades, maintained by superintendent 
Loring B. Walker: 



NAME OF STREET. 


Length of 
steep grade. 


Width of 

macadam in 

feet. 


Max. grade, 

in feet 
per 100 feet. 


Boylston street 

Chestnut street 


6000 feet 
1800 feet 
3000 feet 
3000 feet 
3000 feet 


18 feet 
14 feet 
24 feet 
24 feet 
24 feet 


6 

7 
8 


Sterling street 


Church street 


9 

10 


Main street 







These streets have paved gutters four feet wide. 
Cambridge, Mass., has steep grades on Lancaster 
street, Humbolt street and Washington avenue, main- 

•65 



CITY ROADS AND PAVEMENTS. 

tainecl by superintendent R. A. Brown. Medford has 
a steep grade on High street while there are also steep 
grades, kept in good condition, in Brookline, Chelsea, 
Maiden, Winchester, Woburn and Somerville, Mass. 

On Staten Island, now the Borough of Richmond of 
the city of New York, there were built from 1895 to 
1 90 1, by Henry P. Morrison, M. Am. Soc. C. E., 183 
miles of macadam streets, w^hich include some having 
steep grades which are described as follows : they are 
now in charge of Louis L. Tribus, M. Am. Soc. C. E. : 



XAME. 


T.ength of 
steep grade. 


Width of 

macadam in 

feet. 


Max. grade 


Village. 


Street. 


in feet 
per ICO feet. 


Garretson's . . 


Ocean terrace. . . . 


800 feet 


16 feet 


9 


Garretson's . . 


Prospect avenue. . 


500 feet 


16 feet 


10 


Stapleton. . . . 


Orient avenue 


100 feet 


16 feet 


10 


Stapleton. . . . 


Orient avenue. . . . 


100 feet 


16 feet 


16 


Garretson's . . 


Four Corners' road 


500 feet 


16 feet 


1 1 


Stapleton. . . . 


Trossack road .... 


730 feet 


16 feet 


12 


Clifton 


Hillside avenue 


1600 feet 


16 feet 


12 


Stapleton. . . . 


Occident avenue . 


100 feet 


16 feet 


II 


Stapleton. . . . 


Occident avenue . 


100 feet 


16 feet 


13 


Stapleton. . . . 


Occident avenue . 


100 feet 


16 feet 


14 


Stapleton. . . . 


Occident avenue . 


100 feet 


16 feet 


16 


Stapleton. . . . 


Louis street 


300 feet 


16 feet 


II 


Stapleton .... 


Louis street 


200 feet 


16 feet 


20 



These streets are formed of eight inches of crushed 
trap (except Trossack avenue which is six inches) all 
thoroughly rolled with four inches of crown, and all 
except three have paved gutters. 



CONSTRUCTION OF A MACADAM ROAD. 

The earth roadbed must first be drained, and in flat 
streets where the usual deep side-ditches are impossible, 
there must be shallow brick paved gutters to take the 

166 



SUBGRADE. 

surface water at each side of the street and also porous 
tile drains, two feet below them, to collect the [ground 
water and carry it to the sewers. See jxige lo. 
Curbs will usually be required for a city street. 

SUBGRADE. 

The subgrade, must then be cleared of all soft and 
loose material, preparatory to forming it on the best 
grades obtainable, with a regular crown or con\'e.\ity of 
about one-half inch per foot for any grade up to five 
per cent and for widths up to sixteen feet, and of 
three-fourths inch per foot for steeper grades. (See 
page 36.) Old roadbeds usually have more or less 
hard and firm material beneath the objectionable dust 
and mud, ar.d this firm substratum should be dis- 
turbed as little as possible by establishing the grade 
line high enough to avoid it. 

A steam roller passing over an earth roadbed will 
disclose the existence of a surprising number of yield- 
ing places and soft spots which could never be found 
in any other way, but which can readily be filled, or 
excavated and refilled and re-rolled, until the earth is 
regular and equally hard throughout. 

Instead of first forming the side-ditches and the 
crowned subgrade, as is usually done, it is sometimes 
better practice and easier for the roller to grade the road- 
bed flat in cross-section and at about two inches below 
the desired elevation of the center of the crowned sub- 
grade ; deferring the ditches until the last, unless their 
excavation is at once necessary to provide grading 
material or to take storm water. 

On this flat roadbed, use the roller and adniit trafiic 
until the whole surface is so hard that the wheels of a 

167 



CITY ROADS AND PAVEMENTS. 

loaded wagon leave no ruts. When ready to prepare for 
spreading stone, stake out the proposed macadam and 
drive twenty-four inch by one-half inch steel pins fifty 
feet apart along each edge and stretch a cord at the 
correct elevation of the proposed surface of the base 
course : then use square-end shovels and picks to cut 
down four inches along the cords, sloping the cut to 
nothing at three feet toward the center for a sixteen feet 
roadway, or more for a wider one : throw the excavated 
material into the center to form the crown and roll it 
till firm, making the center at the right elevation and 
forming the desired crown to receive the stone. The 
side ditches can be left to be dug and paved after the 
completion of the macadam roadway. Several expe- 
rienced contractors who have doubtfully tried this 
method, have adopted it as their regular practice. 

All precautions must be taken to secure the per- 
manence and solidity and dryness of the subgrade, and 
it is an economy for the contractor during construction 
to get it as hard as described because this prevents the 
loss of costly crushed stone, and it is also an economy 
in future maintenance by prolonging the life of the 
roadway. 

Broken stone roads have been " built " in cities by 
spreading six inches of good crushed trap upon the 
mud and dust of a soft subgrade with the result of total 
failure within two years. 

Sand Subgrade. — A subgrade of sand which will 
not consolidate even when wet, may be fixed by cover- 
ing with three inches of loam, or of shale or gravel, or 
with a thin layer of broken stone, either of which will 
probably consolidate under the roller after wetting. 
Peculiarly loose sand is sometimes found, into which 

1 68 



SUBGRADE. 

one's arm can be thrust to the elbow, and this has been 
bound as above. Tliis difficult condition is also well 
met in an article entitled " Economic Design of Streets 
and Pavements," by Halbert Powers Gillette, re-printed 
from the Engineering News, in the very complete 1901 
report of the highway commissioner for New Jersey, 
Henry I. Budd, as follows: 

" Sand can be made quite as unyielding as gravel simply by filling 
the voids with fine dust or pulverized sand. No rolling is 
necessary. "Water, if supplied in abundance, will puddle sand 
to which fine dust has been supplied, until the sand becomes 
hard and unyielding." 

A telford base may be required as discussed on page 
152. A layer, one and one-half inches thick, of three- 
quarter inch to one inch broken stone, coated with hot 
bitumen and rolled at once, will serve in an extreme 
case where simpler ways fail. 

Clay Subgrade. — Subgrades of slippery clay showing 
increasing waves when rolled with a twelve ton to fif- 
teen ton roller, have been consolidated, after subdrain- 
ing with buried tiles, by covering the clay with a layer 
of freshly-cut straw and then rolling with a lighter 
roller, ten tons in weight. This has also been done by 
covering the clay with a single layer of quarter inch 
to half inch green brush, rolled into the moist clay 
and then covered with an inch of sand and again 
rolled. 

Small areas or " pockets " of springy wet clay must 
be removed, or must be drained and then covered with 
a layer of gravel or coarse sand. 

Settlhig a Clay Subgrade. — It is sometimes best, and 
has been done with good results, to rough-grade a 
clayey subgrade and to let it stand under traffic for some 

169 



CITY ROADS AND PAVEMENTS. 

months, or better through a winter, before preparing it 
to receive the broken stone. 

Sandy Loam Subgrade. — This is most difficult when 
the particles are very fine, so that the capillary attrac- 
tion prevents sub-drains from taking the ground- water; 
in such case, this part of the road must be watched 
during the first wet season after completion, and if it 
shows signs of yielding under traffic, the layer of broken 
stone must be increased in thickness, as is discussed on 
page 177, in the quotation from W. E. McClintock, M. 
Am. Soc. C. E. 

Various expedients must be tried until one is found, 
by which the subgrade will remain firm and smooth 
when the broken stone is spread and rolled upon it, so 
that the fragments shall not work down into the sub- 
grade, nor the material of the subgrade w^ork up among 
the fragments, under the action of the roller. The 
stone thus saved is worth more than the cost of this 
special work. 

Remove Stones. — Stones or rocks lying within half 
a foot of the top of the subgrade, and which are larger 
than six inches, should be removed, lest they serve as 
anvils on which traffic will crush the road-metal. 

QUALITY OF ROCK TO BE BROKEN. 

The rock should be hard, tough, durable and uni- 
form in character, fracturing with a toothed surface and 
showing a tendency to break into cubes rather than 
into flakes. This latter pecularity occurs with some 
rocks which would otherwise be good, and in one case 
was found to be the direct result of excessive use of 
dynamite in the quarry. 



170 



CRUSllINC. 



The rock should ]ia\'c a compositioii wliicli cements 
wlieii wet and rolled, and should come clean from the 




Tailings larger than ^ inrhe 
to return to cruslirr. 



Wagon loading c rushed 
sloiie from Inn. 



Screens and bins for screenings 
and three sizes of stones. 



Cart dumping rork from r|narr>' 
onto iilallorni over crusher, 

Crnslier prndncina 135 euliic 
j(ls. crushed stone per day. 



CRUSHIXCi AND SCREEXIXG ROCK. 



quarry to the crusher. A softer rock may be crushed 
for the base course, and its screenings will usually form 
a good filler for it. (See page i6i.) 



CRUSHING. 

The crusher should be placed where the rock will 
pass down from the ledge through the crusher and 
through the bins into the wagons, and then down-hill 
to the work. The crusher should be set to produce 
the largest size specified, and the whole j^roduct should 
then be screened through a series of three revolving 

171 



CITY ROADS AND PAVEMENTS. 

screens or cylinders pierced with circular holes, set on 
a slope so that the material passes slowly as the screens 
revolve into separate bins for each size. Thin slabs 
and long pieces and the " tailings," should be re-crushed. 
Sixty cubic yards of solid rock in the ledge allowing 
for quarry w^aste will make about loo cubic yards of 
loose rock which will produce about 125 to 135 cubic 
yards of the different sizes measured separately. 

The following results were obtained in crushing hard 
flinty limestone weighing 168 pounds per solid cubic 
foot, or 2 1 7 1 pounds per cubic yard of quarry frag- 
ments of one to two cubic foot each, of which a mass 
showed fifty-two per cent of voids and 100 cubic yards 
produced as follows: 



Size of screened 


Number 


of 


Weight per 


Per cent of 


products. 


cubic var 


ds. 


cubic foot. 


voids. 


inch to I y2 inch . . 


1 ^5 




1 96 pounds 


43 


J^ inch to ^8 inch. . 




(91.5 pounds 


45-5 


Y^ inch to Y^g- inch . . 


14 




92 pounds 


45-2 


-^-^ inch to dust inch . 


19 




93 pounds 


44.6 



One hundred and eighty cubic yards of quarry-rock 
were crushed in ten hours and the product was 
screened and put in bins and cars at a total cost for 
plant, fuel and wages of fourteen cents per cubic yard 
of product. The usual cost is twenty cents, and with 
a smaller crusher, thirty cents. 

The screens should be selected to produce the re- 
quired sizes, two and one-half inch circular holes giving 
what are known to dealers as " two inch " stone : one 
and one-fourth inch holes giving " one inch," used for 
the binder-coat of asphalt pavement : one inch holes 
giving " three-fourths inch : " one-half inch holes giving 
" screenings : " one-fourth inch holes giving " one-eighth 
inch dust." 

172 




Preparing subgrade. 




Finishing' subgrade. 




.ifHi 




T 






Ill^dP?-;-; .^ - ■ ,:rJ^i^l^i^A 



Snreading and 1 



111 lation stone. 



RIVER-ROAD NEAR BLFlALt), NEW YORK. 

Surface of two inches of trap rock on base of four inches of limestone. 

Built by State Engineer E. A. Bond, :\I. Am. Soc. C. E., in 1900. 



CITY ROADS AND PAVEMENTS. 

The required sizes vary as indicated in the foHowing 
table showing the practice during 190 1-2 in the States 
named : 

Sizes of Broken Stone and Thickness of Courses, in Inches. 







Lower Course 
OF Macadam. 


Upper Course 
OF Macadam. 


Surface. 

i 




STATE. 


Size of 
Frag- 
ments. 


Thick- 
ness 
after 
roll- 
ing. 


Size of 
Frag- 
ments. 


Thick- 
ness 
after 
roll- 
ing. 


Size of 
Frag- 
ments. 


Thick- 
ness 
after 
roll- 
ing. 


Size 

not 

used. 




Min. 


Max. 


Min. 


Max. 


Min. Max. 




Kew Jersey 

Massachusetts. 
Connecticut . . . 
New York 


IK 


3 

2 

3 


4 
4 
4 
4 


1 

1 

1 




IK 
2 




2 




dust 
dust 
dust 

dtist 


y^ 


smooth 
surface 
smooth j 
surface 
1 


Ktol 

none. 
Ktoi 

none. 
* 



* Oiie-lialf inch to one inch spreail on siib^rade as oiie-tliiid of the base course. 



FORMATION OF LOWER COURSE. 

The thickness of the layer of loose stone spread for 
this course should be gauged by five and one-half inch 
cubes of wood placed upon the subgrade, including a 
bottom layer not more than one and one-half inches 
thick of that part of the crusher product not otherwise 
required. 

The stone should be uniformly spread to this depth, 
beginning furthest from the source of supply in order to 
avoid driving over the loose stone, and using spreader- 
wagons to uniformly distribute it. If ordinary wagons 
are used, the stone should be shoveled from the wagons 
or from the roadside. - If dumped in large piles upon 
the subgrade of the road, the position of each pile will 
be made evident after the road is finished. When sev- 
eral hundred feet of roadway have been covered, the roll- 
ing should begin along each edge, lapping on to the 

174 



FORMATION OF TOP COURSE. 

earth shoulder aixl rollinij^ cacli side several times iiiuil 
the fragments do not ereep or weave before the roller 
when they will be compressed to four iiiches. No 
screenings or water should be put on till after this: 
the use of dry screenings is described on page 159. 

When the lower course is properly filled and bound 
it will be so firm and solid that loaded wagons can pass 
over it without leaving an)' mark, but the surface of 
the stone should be free from screenings. 

FORMATION OF TOP COURSE. 

The top course, perferably of trap, is then spread in 
the same manner, using two and three-fourths inch 
gauge-blocks and rolling the loose stone to two iiiches, 
and until the fragments do not creep and weave, before 
spreading the dry screenings as described on page 160. 
Sometimes it is required that the rolling of the top 
course shall continue until the material is packed so 
firmly that an inch cube of trap laid upon the finished 
surface shall crush under the roller without sinking 
into the road surface. 

A properly made macadam pavement resembles a 
mass of concrete, and in several cases has proved self- 
supporting when the earth beneath it has been washed 
out by floods. 



/D 



CITY ROADS AND PAVEMENTS. 



r ■ ( 


' .-!^^^^^^|H^^^HHHHi 




j f^i '^^^^^^^^^^^^^^^^H 


f ■, 


^fe^ ^H^^^^^^^^^^^^^H^^hJ^^^hBI^^^^I 


, 


i W'l^^^^^^H^^IHH 


f . 




, 






' ' ii^^^^KK^^ 


r 




\ - 




1 
1 






.jh'uM^^^^^K^M 



o 
< 



g 

3 

< 

c^ 
w 
> 

o 

o 

I— I 

e 
w 

o 

I— ( 

>1 

I— I 

cc 

O 
P^ 

< 
Q 
<J 
o 



Smooth surface uf roadway. 



Cave made by washout. 



1/6 



CROWN OR SLOTK OF MACADAM SIKIACK. 
THICKNESS OF IJROKEN STONE FOR MACADAM ROADWAYS. 

Careful studies lia\e been made b)' \\\ E. McCliu- 
tock, M. Am. Soc. C. E., as to the bearing power of 
various soils in order to adjust the thickness of the 
layer of broken stone to suit the soil and the traffic. 
His valuable conclusions are given in the 1901 rejDort 
of the Massachusetts highway commission, of which 
he is Chairman, as folloW'S : 

'• The Commission has estimated that non-porous soils, drained of 
ground-water, at their worst will support a load of about four 
pounds per st^uare inch ; and having in mind these figures, the 
thickness of the broken stone has been adjusted to the traffic. 

" On a road built of fragments of broken stone, the downward pres- 
sure takes a line at an angle of forty-five degrees from the hori- 
zontal, and is distributed over an area equal to the square of 
twice the depth of the broken stone. If a division of the load 
in pounds, at any one point, by the square of twice the depth 
of the stone in inches, gives a c}uotient of four or less, then will 
the road foundation be safe at all seasons of the year. On sand 
or gravel the pressure may safely be placed at twenty })ounds 
per square inch. 

''Acting on this theory, the thickness of stone varies from four inches 
to sixteen inches, the lesser thickness being placed over good 
gravel or sand, the greater over heavy clay, and varying thick- 
nesses on other soils. In cases where the surfacing of broken 
stone exceeds six inches in thickness, the excess in the base may 
be broken stone, stony gravel or ledge stone ; the material used 
for the excess depending entirely upon the cost, either being 
equally effective." 

CROWN OR SLOPE OF MACADAM SURFACE. 

The convexity or crown of the roadway is usually 
made one-half inch to three-fourth inch per foot each 
way from the center-line for widths up to sixteen feet 
and one-half inch per foot for wider cit\' streets. (See 
page 36). 

177 



CITY ROADS AND PAVEMENTS. 

The curve must be regular so that no water can 
stand upon the surface and must be continued uniformly 
over the wings to the ditches or gutters at the sides so 
that water will run off freely. 

The roadway may have a plane surface, sloping 
wholly to one side, with good results. This construc- 
tion is sometimes desirable when a street-car track 
occupies one side of the roadway and where it is neces- 
sary to drain the surface to one side : or when car-tracks 
occupy the center of the roadway and the macadam on 
each side must drain wholly to the ditch on that side. 
A nearly flat city street with forty feet width of mac- 
adam sloping regularly one-half inch per foot from one 
side to the other gave no trouble and was found in 
perfect order after several years use. 

COST. 

The cost of broken-stone roads varies with the local 
conditions and the supply of stone: the following 
approximate figures are for six-inch macadam complete, 
not including curbs or grading or drainage : 

With local stone available, suitable for both base and 
top and filler, forty-five to fifty cents per square yard. 

With local stone available for base only, top and filler 
coming from a distance, sixty to sixty-five cents per 
square yard. 

With no good local stone, all coming from a distance, 
seventy to seventy-five cents per square yard. 

For resurfacing roads, for which local stone is avail- 
able as in Massachusetts, the average cost is ten cents 
per square yard for each inch in thickness. 



178 



CAUTIONS. 
THINGS TO BE AVOIDED. 

The work should be so planned, and the traffic so 
diverted that there will be the least possible passing of 
wheels over the loose stone which have been spread to 
form the base course, or the top course, of a macadani 
roadway. The stones should be at once rolled, and 
should be bound together as soon as possible, in order 
to preserve the angles and the roughly fractured sur- 
faces which would be rounded and worn smooth by 
traffic. 

No screenings or sand, or earth from the subgrade, or 
"filler" or binder of any kind, should be allowed upon 
or among the regular fragments of loose stone until 
they shall have been thus rolled and consolidated. It 
will be difficult, if not impossible, to properly bind the 
stones if any " filler " gets between the fragments while 
they are loose. 

Excessive rolling will injure the road, especially if 
there has been too much wetting, or if the stone is 
either soft or brittle. Experience is the only safe 
guide. 



179 



MAINTENANCE. 



Broken-stone roads require constant care beginning 
as soon as they are opened to traffic. The cost is less 
for continuous attention than for deferred repairs. 

The system of roads which was built early in this 
century all oyer England, required then, and still con- 
tinues to require, the constant attention of an army of 
resident \yorkmen liying along the line of the roads and 
making neyer-ceasing repair of ruts and breaks as soon 
as they occur. Little piles of broken stone, or of stone 
to be broken, \yere and are neyer-absent eyidences of 
constant care, and steam road rollers are often met 
when driying through the country. Such care is 
necessary and costly. 

In London and in Paris broken-stone roads are the 
roads of luxury; some of the finest streets haying mac- 
adamized central driyeways, bordered on each side by 
thirteen feet of sheet-asphalt. 

In Paris the annual cost of maintenance of suburban 
macadamized streets haying light traffic is about one- 
third the original cost of building them, hi some cases 
of extra heayy city traffic, the annual care costs one- 
third more than the original building; that is, the 
roadway fourteen inches thick has to be practically 
renewed eyery nine months. In such cases macadam 
is more costly than asphalt or wood blocks, which are 
therefore replacing it. 

1 80 



BROKEX-STONE ROADWAY. 




■s. < 



iSl 



CITY ROADS AND PAVEMENTS. 

The rocks available and used for broken-stone roads 
in Paris are inferior to those used in and about New 
York. Edward P. North, M. Am. Soc. C. E., in his 
standard book, " Construction and Maintenance of 
Roads," states that of the Paris broken-stone roads, 
"sixty-seven per cent are made of meuliere^ twenty-three per 
cent of porphyry and ten per cent of water-worn flint pebbles." 
Meuliere is a quartzite in which coarse grains of 
quartz are united by a peculiarly strong silicious cement. 
Neither the meuliere, the porphyry nor the flint is equal 
in durability to diabase trap. 

The good condition of the Paris broken-stone roads, 
in spite of their indifferent materials, is the result of 
the perfect system of care which the French have 
learned to give to all their roads. One of the important 
avenues thus paved is the well-known driveway through 
the Bois de Boulogne. 

In any case, eternal vigilance and a continuing sup- 
ply of money are the price of a good system of mac- 
adam city roads. 

Raveling. — Loosening of the surface-stone, or " rav- 
eling" is the most common defect, and this is checked 
and prevented by covering the traveled surface with 
half an inch of coarse sand or of trap-rock or other 
screenings, and by renewing this whenever it is dis- 
placed by traffic, by storm-wash or by wind. This layer 
prevents the toe-calks of horses from loosening the frag- 
ments of stone, and retards evaporation from the binder 
in which the fragments are embedded. 

When the surface shows any loose fragments, these 
should be promptly restored to place if possible, or 
removed to one side, and the road should at once be 
thoroughly wetted, sanded and rolled. 

182 



MAINTENANCE. 

Rolling. — Rolling is of special importance in the 
spring, as soon as the frost is gone and before tlie road- 
way becomes hard and rigid; or during a soaking rain- 
fall while the road is somewhat plastic : the edges 
being rolled before the center, to restore and preserve 
the crown. This treatment will go far to keep the road 
in good condition for the rest of the year, especially if 
the traveled way is then covered with half an inch of 
sand or of screenings ; never with clay, ashes or loam, 
unless fully mixed with three to four times their bulk 
of coarse, sharp sand. 

Ritts. — When short ruts appear, as they sometimes 
will in the best of roads, especially during the first 
spring, the top layer of stone — usually two inches thick 
— should be taken out for a width a few inches more 
than the rut and for its full length. This will make a 
regular hole, which is slightly deeper in the middle 
than at the sides, and in which the fragments of stone 
should be replaced with a few additional ones of the 
same sizes and kind : the larger fragments being placed 
in the deeper center and the smaller ones toward the 
edges. 

The loose fragments must then be rammed with a 
paving rammer and packed and consolidated until level 
with the adjoining old surface. Screenings or sand 
must then be added and brushed to fill the voids, with 
a final free sprinkling to aid the binding and last ram- 
ming until the patch appears as firm as the rest of the 
road and the surface has been perfectly restored. A 
small rut can be thus repaired by one man in a few 
minutes so that the place cannot be found the next day. 
Special care is necessary that the patch is made no 
higher than the adjoining surface, as an elevation of 

183 



CITY ROADS AND PAVEMENTS. 

even half an inch may cause ruts to form around the 
patch. When long ruts appear, as they sometimes do 
in the spring before the road has been rolled, put picks 
in one roller-wheel and run it along the rut, loosening 
the surface, which then level into the rut and then wet 
and roll smooth. 

Sometimes a rut consists of a slight depression be- 
tween two slight ridges, and this condition can be 
easily corrected when rain-soaked by rolling down the 
ridges with the wheels of a broad-tired wagon in which 
a heavy load of stone is piled over the rear axle. 

Ruts and hollows are best found and repaired during 
rainy w^eather. 

Stones of a smaller size than the original top layer, 
or of a different kind of rock, should never be used for 
repairs, as the small fragments crush more readily than 
larger ones, and different kinds must wear unequally. 
It is not well for instance, to repair a trap rock road 
with patches of limestone, or the reverse. 

The common practice of spreading and leaving two 
inches or more of loose " three-quarter inch stone " 
in the ruts and upon the surface of a worn mac- 
adam road, is wasteful of material and needlessly 
annoying to traffic, which should never be compelled 
or allowed to pass over loose broken stone. It costs 
less to spread a thin layer of larger fragments as de- 
scribed, and to at once pack it by using a steam roller. 

Cleaning. — Mud must be scraped from the surface 
of a broken-stone roadway whenever it becomes deep 
enough to show tracks and to hold water. If mud is 
allowed to accumulate to a general thickness of one to 
two inches, and to remain, it will work down between 
the fragments of stone and eventually will destroy their 

184 



COST OF MAINTENANCE. 

bond. Wlicn this condition lias l^ccn readied, resur- 
facing the road will niean re-building it at a greater 
cost than to have kept it clean. 

SJiottlders and DitcJics — These must be kept in regu- 
lar form, and the washouts filled, and the ditches cleared 
of sediment and dead leaves, and freed from growing- 
weeds and grasses. 

Cost, — Definite figures for this work on city streets 
are not easily kept separately, but the accounts of the 
expenses of thus maintaining rural broken-stone roads 
have been closely kept by the Massachusetts highway 
commission for several years and are given during 1901 
for 166 roads with a total length of 334 miles. 

Six of these roads, with a total length of seven miles, 
w^ere evidently extreme cases and are not here included. 

The remaining 160 roads, 327 miles long, ranged in 
cost of maintenance from about $4 per mile to about 
$300 per mile and averaged #70 per mile. The mac- 
adam surface of these roads is usually fifteen feet wide, 
being 8800 square yards per mile, and this at $70 
equals eight-tenths per cent per square yard per year 
for maintenance. 

RE-SURFACING. 

A trap-rock road will ordinarily endure for several 
years without re-surfacing, but a limestone road will 
need it much sooner, because it wears faster and blows 
away more readily. 

Whenever the surface of any broken-stone road 
becomes worn and irregular and the lower stones are 
exposed in spots, it needs re-surfacing. The street 
should be treated in sections 300 or 400 feet long, or 
as much as the force can begin and finish each day. 

185 



CITY ROADS AND PAVEMENTS. 

The steam-roller with picks in the wheels should be 
run over half of this section to loosen the top layer. If 
mud is found to be mixed with the fragments of stone 
in the road, rakes and potato-forks must be used to 
separate and save the stones, which can be used again 
with the addition of enough new stone of the same size 
and kind (usually trap rock) to restore the original 
thickness. If the road has been kept properly free 
from mud, it will only be necessary to add to the loos- 
ened top a single layer of one-inch to two-inch frag- 
ments, and to roll them into the loosened top layer, until 
all is solid and firm, binding with sand or with screen- 
ings, and wetting and rolling until a wave of "grout" 
goes before the roller, from which the picks have of 
course been removed. The operations can then be 
repeated on the other half, and the section opened to 
traffic the next day. 

Cost, — This re-surfacing will require about 300 cubic 
yards of loose stone and about fifty cubic yards of 
screenings per mile of fifteen-foot roadway, the cost of 
which will vary with the freight charges. In Massa- 
chusetts, where there are no long hauls by railroad, 
the cost is $700 to $880 per mile, or eight cents to ten 
cents per square yard of surface for each inch of fin- 
ished thickness of the broken stone. 



186 



INDEX. 



PAGE. 

Abrasion tests — brick, 88, 89 ; broken stone 145, 149 

Albany, N. Y.— asphalt, 26, 118, 120. 130; block stone, 26, 64; brick, 
86, 95, 98, 130 ; limestone near, 141 ; plank roads, 67 ; railroad, first 

passenger road, 20 ; wheel tracks, stone 19 

Alexandria, La. — brick , 100 

Alton, III. — brick 84 

Alleghany, Pa. — asphalt, 20 ; block stone, 26 ; brick 84, 99 

Altoona, Pa. — asphalt 56 

Ancient pavements 17 

Annapolis, Md. — asphalt block, 128; brick 100 

Asphalt pavements 103 

American sheet asphalt — 

Artificial mixture 104 

Asphalt.... 109 

Sources of 108 

Base 112 

Binder 112, 113 

Care in building- 110, 111 

Cost 56, 120 

Failures, causes of 124 

Complete 

Cracks 

Disinteirration by fires, gas, kerosene 126 

Foundation — brick, cobbles, concrete, macadam, stone 

blocks 112 

Guarantee 108, 120 

Materials and methods 109 

Preference for, comparative, 130 

Proportions 110 

Rolling 114 

Sand 110,111 

Wearing surface .- 114 

Crown 30, 118 

Grades, steep 118 

Block asphalt 127 

Cost 128 

Extent, materials, proportions 127 

Use 129 

Leuba blocks . 128 

Companies 107 

Extent of use 104 

History 103 

Atchison, Kan. — brick 84, 100 



187 



INDEX. 

PAGE. 

Atlanta, Ga.— asphalt, 26, 56, 118, 130; brick, 84, 95, 130; blo(;k 

^tone 26, 64 

Aurora, III. — asphalt IJO 

Baltimore, Md.— asphalt, 56, 120, 130; concrete-mixer, 51; brick, 98, 130 

wood blocks 78 

Bbllaire, Ohio — brick 84 

Binghampton, N. Y.— asphalt, 130; brick 84, 95, 130 

Birmingham, Ala. — brick , . 100 

Bituminous macadam pavements, 131 ; construclion, 132, 133 ; cost, 134 ; 
extent, guarantee, grade, 135; opinions and results, 137; propor- 
tions, 131 ; use , 136 

Block stone pavements 57 

Cost , 63 

Defects ,.. .... 59 

Joints, filler for 62 

Kinds of rock — 

Granite 57 

Sandstone, 61 

Trap 57 

Merits 61 

Mileage 64 

Strength 61 

Bloomington, III. — brick 84 

Boston, Mass. — asphalt, 26, 36, 56, 130 ; block stone, 26, 36, 64 ; brick, 

130 ; macadam, 138 ; wood block 36, 65, 67, 73, 78 

Brick pavements 82 

Construction of 92, 95 

Base for 92, 94 

Cushion of sand 34, 92, 95 

Joints, expansion 97 

Filleis of joints, 96 

Cost of. 99 

Paving cement, bituminous 96 

Portland cement 93, 96 

Sand 96 

Cost of 84, 98, 100 

Crown ....33, 95 

Curb , 39 

Extent 82, 85. 91, 130 

Failures of 86 

Fusion of material 87 

Guarantee 101 

Material 87 

Noise 85, 96 

Preference for, comparative 130 

Qualities ; hard, strong, tough 89 

Reaction against use 85 

Region of production 86 

Rolling 93 

Steep grades for 98 

Success of - 87 

Tests- 
Abrasion 88, 89 

Absorption 90 

Examination in use 81,83, 90 

Brocton, Mass. — bituminous macadam 135 

Broken stone roads 1^8 

Macadam pavements — 

Binder for l.'^6, 157 

l88 



INDEX. 

PAGE. 

Broken stone roads — (Cotituiiied) — 

Modes of use ; En^^land, France, 157 ; Connecticut, New 

Jersey, 158; Massachussets, New York 159 

Quality; limestone, trap, 160, p^ranite, 161; sainl, 

157, 159, 161 

Quantity 161 

Screenings 156, 160 

Cautions 179 

Construction 16t) 

Cost 178 

Courses — 

Lower 174 

Roiling 174,175 

Thickness 177 

Top 175 

Crown 36, 1 67, 177 

Curve of 34,178 

Grades, steep 162 

Gutters, paved 1 65 

Rolling- 
Courses — 

Lower . — 1 74 

Top 175 

Excessive 179 

Subgra.le 12,167 

Screening's (See Bindei ) 156, 160 

Sprinkling 159-160 

Subgrade — 

Clay 169 

Drainage 8 

Dryness ... 168 

Loam 1 70 

Sand 168 

Stones in 170 

Sub-drainage - 10, 169 

Stones — 

Loose 179 

Screenings 172 

Sizes 174 

Sub-grade 170 

Maintenance — 

Cleaning' 184 

Cost 180-185 

Raveling 182 

Re-suT facing 185 

Cost J86 

Rolling 183 

Ruts 183 

Stone for 183 

Rock for roads — 

Cobbles .. 143 

Crushing 171 

Flint 182 

Granite 140 

Limestone 141 

Meuliere 182 

Porj)hyry 140 

Quality 170 

Quartzite 140 

1S9 



INDEX. 

PAGE. 

Broken stone roads — (Continued) — 

Sandstone 143 

Sizes 172, 174 

Tests 146 

Machine for 145 

Results of.. 148, 149 

Trap 139 

Uniformity 143 

Sand for binder 157, 159, 161 

Screens 172 

Systems 150 

Cost, relative 153 

Macadam. 150 

Telford 150-153 

Telford pavements 150-1 53 

Construction 151, 154, 1 55 

Cost 153 

Defects , 152 

Extent., 154 

Merits 153 

Mileage , 139, 156 

Sizes of stones 154 

Brookline, Mass. — macadam 138, 166 

Buffalo, N. Y.— asphalt, 26, 36, 56, 104. 118, 119, 121, 130; block 
stone, 26, 36, 61, 64 ; brick, 84, 95, 130 ; limestone near, 141 ; mac- 
adam streets, 38 ; wood blocks , 36 

Burlington, Ia, — brick 84 

Cambridge, Mass. — bitaminous macadam, 132, 135 ; brick, 92, 93 ; 

macadam 138, 1 65 

•Car Tracks — construction of 40 

Cattskill, N. Y.— brick 86 

Cedar Rapids, Ia.— asphalt, 120 ; brick 84 

Charleston, S. C. — asphalt, 118; bituminous macadam 135 

Charleston, W. Va. — brick 84 

Chattanooga, Tenn. — asphalt 56 

Chelsea, Mass — macadam 165 

Chicago, III.— asphalt, 28, 36 ; block stone, 26, 36, 64 ; brick, 84 ; cedar 

block, 26, 86, 67 ; curbs, 39 ; wood blocks 68, 77 

Chillicothe, Ohio— asphalt block, 128 ; brick 99, 100 

Cincinnati, Ohio — asphalt, 26, 56, 120 ; block stone, 26, 64 ; brick 84 

Cleveland, Ohio— asphalt, 56, 130 ; block stone, 61, 63, 64 j brick, 91, 

130; curbs, 39 ; bituminous macadam 135 

Clinton, Ia. — brick 84 

Clinton, Mass. — macadam 165 

Cobble pavements 21, 57, 58 

Columbia University ; tests of materials . , 146 

Columbus, Ohio— asphalt, 26, 56, 120, 130 ; block stone, 26, 61, 64 ; 

brick 84, 90, 91, 95, 98, 100, 113, 118, 130 

Concrete 42 

Aggregates 47 

Base 42 

Bond 52 

Brine 54 

Cement (see Hydraulic cement) 43 

Results of tests ... 46 

Cost 55 

Crusher dust 47 

Freezing- — 

Avoid 54 

I go 



INDEX. 

PAGE. 

Concrete — ( Continued) — 

Limit of cold 54 

Mixing — 

Hand 48 

Machine 50 

Monolith.. 52 

Plastering- 58 

Proportions , 48 

Sand 48 

Loam in 48 

Pit 48 

Washing" 48 

Setting , 58 

Surface 53 

Water 49 

Wetting 58 

Cost of rAVEMENis 26, 56, 84, 100, 120, 128, 135, 153, 178 

CoNNELLSViLLE, Pa. — brick , 84 

Cornell University — tests of materials 147 

Cortland, N. Y. — asphalt 120 

Council Bluffs. Ia. — brick 84, 100 

Crown of pavements — 30 ; lornmLne for, 30, 32 ; form of, 34 ; asphalt, 

33-118 ; brick, 33, 95 ; wood block, 33 ; macadam 36, 167, J 77 

Culverts — cast iron, 37; concrete, 37; masonry, 37; vitritied i^ipe... 37 
Curbs — blue stone, 38 ; brick, 39 ; concrete, 3y ; cost, 40 ; combined, 8i) ; 
corners, 40 ; granite, 38 ; limestone, 38 ; sandstone, 38 ; setting, 38 ; 

sizes 39 

Davenport. Ix. — brick 84 

Dayton. Ohio— asphalt, 118, 130 ; brick, 84, 91, 95 130 

Decatur, 111. — brick 84 

Denver, Col. — asphalt, 26, 36 ; block stone 26 

Des Moines, Ia.— asphalt, 56 ; brick, 84, 98. 100 ; cedar blocks 68 

Detroit, Mich.— asphalt, 26, 118, 130 ; block stone, 26 ; brick, 84, 91, 

95, 130 ; cedar blocks 68 

Dubuque, Ia — brick 84 

DuLUTH, MiN2i. — cedar blocks 68 

Dunkirk, N. Y.— briok 84 

Dirt roads — 7; rolling, 12 ; smooth in winter 12 

Drainage— 8; sub-drains 9, 10 

Elmira, N. Y.— asphalt, 118, 130; brick 95, 130 

Erie, N. Y.— asphalt, 118, 130; brick 95, 98, 180 

Evansville, Ind. — brick 84 

Falls — of horses ,. 36 

FiNDLAY, Ohio — brick 84, 100 

Fort Wayne, Ind.— asphalt. 56, 118, 129, 130; brick 84, 95, 130 

Oalve»ton, Tex. — yellow pine blocks 68 

Galbsburg, It,l. — brick 84 

Garrett, Ind. — brick 100 

Glens Falls, N. Y— brick 97 

Grand Rapids, Mich.— asphalt, 118, 130; brick. 95, 130 

Hannibal, Mo — brick 84 

Harrisburg, Pa. — asphalt, 118, 130; brick 95, 180 

Hartford, Conn — asjihalt, 118 ; brick 84 

Barvard University — tests of materials 146 

Hoi yoke, Mass. — bituminous macadam 185, 186 

Houston, Tex —asphalt, 118, 120, 130; brick ..95, 180 

Hydraulic cement — 
Natural — 

Use of. 43, 56 

191 



INDEX. 

PAGE. 

Hydraulic ce.raent— (Continued) — 

Tests of. 43 

Proportions 48 

Portland — 

increase of 42 

Proportions 48 

Tests of 43 

Chemical 45 

Coloring- 46 

Fineness - 43 

Hot water 44 

Purity 44 

Results 46 

Weig-hts 46 

Use of 47 

Blending- 47 

Indianapolis, Ind. — brick, 84; wood blocks 69, 70, 76, 77 

Jackson, Mich. — asphalt, 118, 130 ; brick 95, 130 

Jacksonville, 1 ll. — brick 84 

JoLiET, III.— asphalt, 1 1 8, 120, 130 ; biick 95, 98, 130 

Johns Hopkins University — tests of materials 147 

Kansas City, Kan. — asi:>halt, 26, 56 ; block stone, 26 ; cedar block 26 

Kansas City, Mo.— asphalt, 26, 126; block stone, 26; brick, 84, 97; 

cedar blocks, 26 ; cypress blocks. 68 

Keokuk, Ia. — brick. 84 

Kenosha, Wis. — brick 84 

Kewanee, III. — brick 99, 100 

Kingston, N. Y. — wheel tracks, stone 22, 23 

Lafayette, Ind. — asphalt, 56 ; brick , 84 

Lancaster, Pa. — brick 84 

Lexington, Ky. — brick , 84 

Lincoln, Neb. — brick. 84 

Little Falls, N. Y. — jrranite near . . 141 

LocKPORT, N. Y. — brick 84 

Long Island City, N. Y. — asphalt 123 

Los Angeles, Cal — asphalt 56 

Louisville, Ky. — brick ... 84, 91 

Loads, comparative 25 

London — Australian hardwood blocks 71 

Macadam 180 

Lowell, Mass — bituminous macadam. 132, 135 

Macadam pavement— (See Broken Stone Roads, 138) 

Malden, Mass — macadam 1 65 

Mansfield, Ohio.— asphalt, 118, 130; brick 95,98, 130 

Marion, Ohio.— asphalt, 118, 130; brick 130 

Massillon, Ohio. — brick 84 

Melbourne, Australia. — hardwood blocks 74 

Medford, Mass — macadam 138, 166 

Memphis, Tenn. — brick 84 

Meriden, Conn. — asphalt, 118; brick 95 

Milw. ukie, Wis.— asphalt, 26, 56, 118, 120, 130 ; block stone, 26 ; 

brick, 95, 98. 130 ; cedar blocks 26, 68 

Minneapolis, Minn.— asphalt, 26, 130 ; block stone, 26 63 ; brick, 130 ; 

wood block , 26, 68 

Montreal, Canada. — asphalt, 56 ; tamarack blocks 68 

Mdncie, Ind. — asphalt 118 

Nashville, Tenn. — brick 98 

Neuchatel, Switzerland — asphalt blocks 128 

Newark, N. J. — asphalt. 104 

192 



INDEX. 

r.v(;E. 

New Bedford, Mass — bituminous macadam 135 

New Cumberland, W. Va. — brick 87 

New Haven, Conn. — asphalt, 130 ; brick 130 

New Orleans, La.— asphalt, 2G, HG, 5G, 118, 120, 130 ; block stone, 26, 

36 ; brick, 95, 130 ; wood block 36 

Newport News, Va. — asphalt 56 

New RocHELLE, N. Y. — woodblocks 78 

Newton, Mass. — macadam 138, 164 

New Yor:-: City, boroughs of 
Brooklyn — 

Asphalt 26, 28, 36, 56, 106, 117, 126 

Block stone 26, 36, 64 

Cobbles . .. 58,116 

Curbs 38 

Macadam 139 

Bronx — 

Asphalt 107 

Macadam . . . , 139 

Manhattan — 

Asphalt 26, 36, 56, 102, 104, 107, 113, 118, 121, 126 

Asphalt block 127, 129 

Bituminous macadam 135 

Block stone 26, 36, 59, 64 

Cobbles 58 

Curbs 38 

Macadam 139 

Wood blocks 'M, 67 

Queens — 

Macadam 139 

Richmond — 

Macadam 139, 166 

Niagara Falls, N. Y. — asphalt base, 55 ; brick 97 

Norwich, N. Y. — bituminous macadam 135 

Oakland. Cal. — redwood blocks 68 

Olean, N. v.— brick 84 

Omaha, Neb.— asphalt, 26, 36, 56, 118 ; block stone, 26, 36 ; brick, 84 ; 

cypress blocks, 68 ; wood block 36 

Oswego, N. Y. — asphalt, frontispiece, 120, 126 ; block stone, 26 ; brick, 

frontispiece 

Ottawa, III.— brick 84 

Owensboro, Ky\ — asphalt 120 

Paris — asphalt, 103; concrete base, 53; macadam, 180, 181, J82; 

wood blocks 70 

Parkersburcj, "W. Ya. — brick 98 

Pawtucket, R I. — bituminous macadam 135 

Peoria, III —asphalt, 56, 118, 120, 130 ; brick 84, 95, 98 

Philadelphia, Pa. — asphalt, 26, 36, 104, 130 ; block stone, 26, 36, 64 ; 

brick, 84, 87, 98, 130; wood block 36, 67 

Pittsburg, Pa. — asphalt, 26, 56, 118, 119 ; block stone 26 

Pontiac, Mich — asphalt block 128 

Portland, Me. — asphalt, 26 ; block stone 26 

Preface , 5 

Pressure — of wheels, 13 ; of structures 15 

Providence, R. I. — asphalt, 26, 56 ; block stone, 26; brick ,84, 99 

QuiNCY, III. — brick - 84 

Rails — S])lices of, 41 ; stone 21 

Richmond, Va. — block stone 64 

Rochester, N. Y.— asphalt, 26, 56, 119, 120, 130; block stone, 26, 61, 
62, 64 ; brick, 84, 100, 130 ; car tracks 40, 41 

193 



INDEX. 

PAGE. 

RocKFORD, III. — brick 84 

Rock Island, III. — brick 84 

ROLLIN G . . „ 10 

Dirt roads 12 

Roman roads 17 

Construction of 18 

Cost of , 18 

Thickness of 16 

RoNDouT, N. v. — wheel tracks, stone 23 

St. Joseph. Mo.— asphalt, 118, 130; brick 98, 100, 130 

St. Louis, Mo.— block stone, 64 ; brick 81, 83, 90 

St. Paul, Minn.— asphalt, 26, 56, 118, 120, 130 ; block stone, 26. 63, 64 ; 

brick, 84, 95, 100, 130 ; cedar block, 26 ; curbs 39 

Salem, N. J. — Bituminous macadam 135 

Salt Lake City, Utah — asphalt „ ,, 118 

San Ai^tonio, Tex. — asphalt, 56, 120 ; mesquite blocks 68 

Sand — 

Cushion 34, 95 

Binder for macadam roads 157, 159, 161 

Filler for joints 61, 96 

Strewn on pavement 28, 71, 121 

For concrete c 48 

Washing 48 

Sandusky, Ohio— asphalt, 118, 120, 130 ; brick 95, 130 

San Francisco, Cal. — asphalt, 56, 106, 118; block stone, 26; redwood 

blocks 68 

ScHEN ectady, N. Y. — wheel tracks, stone 19, 22 

ScHU ylerville, N. Y. — trap-rock near 140 

ycRANToN, Pa. — asphalt, 56, 118, 130; brick 84, 95, 130 

Sewers — increased size 8 

Sidney, N. S. W. — concrete base 53 ; Australian hard-wood blocks.... 71 

Somerville, N. J. — macadam and teltord streets 153 

Somekville, Ma!?s. — macadam streets 165 

Splices of rails — electrical, 41 ; cast iron 41 

Spokane, Wash. — asphalt 56 

Springfield III. — brick .... 84 

Springfield, Mass. — asphalt, 118, 130 ; I rick, 95, 130 ; macadam, 138 ; 

wood blocks , , 78 

Sprinkler , 12 

Steam railroad, first passenger railroad , 20 

Steam roller , 11 

Weight 12 

Tests 12 

Durability ... 13 

Steep grades — asphalt, 27, 118 ; bituminous macadam, 30, 135; block 
stone, 28, 29 ; brick, 28, 98 ; broken stone, 29, 164, 166 ; wood block. 29 

Stone rails 21 

Stonk wheel-tracks (See Wheel-Tracks) 18 

Streets — residence, 7 ; width of 8 

Sub-grade — drainage of, 9 ; rolling of, 42 ; test of. 42 

Steueenyille, Ohio — brick , 84 

Superior, Wis, — cedar blocks 68 

Surface — crown of, 30, 95, 118 ; reduction of, 7; ideal, 30; curve ot, 34 

Syracuse, N Y, — aspha't, 26, 28, 118 ; block stone, 26 ; brick 84 

Taunton, Mass. — bituminous macadam 135 

Terre Haute, Ind —asphalt, 118, 130: brick, 84, 91, 95 130 

Tests— brick, 88, 89; cement, 43 ; stone 145, 149 

Toledo, Ohio— asphalt, 26, 56, 118, 120, 130; asphalt block, 128 ; block 
stone, 26, 61,64; brick ..-84, 91, 98, 100, 130 

194 



INDEX. 

PAGE. 

Tolls 20, 23, 67 

ToPEKA, Kan. — brick , 94 

Toronto, Canada — asphalt, 56, 118, 130 ; brick, 95, 130 ; cedar blocks, 68 

Traffic, pressure of. 13 

Troy, N. Y.— asphalt, 118, 130; block stone, 64; brick 84, 95, 98, 130 

Utica, N. Y— asphalt, 26, 56 ; block stone 26 

Waltham, Mass. — macadam 165 

Washington, D. C— asphalt, 26, 36, 56, 104, 107, 109, 130 ; asphalt 
l)lock, 127 ; block stone, 26, 36, 64 ; brick, 84, 130 ; curbs, 38 ; wood 

block . , 36 

Watbrtown, N. Y. — brick 84 

Wheeling, W. Va.— brick 84, 98 

Wheel-Tracks, stone 18 

Albany, N, Y 19 

Kingston, N. Y 23 

Schenectady, N. Y 19 

Costof 21, 24 

Wide tires 13 

Wilmington, Del. — block stone, 26 ; brick 84 

Winchester, Mass. — macadam 165 

Winnipeg — asphalt 56 

Wobdrn, Mass — macadam 165 

Wood pavements 66 

American, latest types 74 

Creo-resinate 78 

Cost ; g-uarantee 80 

Creosote, quantity of ; details, 79 

Localities 78 

Pine heartwood ; ros n ; treatment 79 

Kreodone-creosote 77 

Cost ; creosote, quantity of 77 

Details; guarantee; localities 77 

Treatment.. — 77 

American, older types — 

Cedar blocks, round 26, 67 

Cost ; details ; extent 67, 68 

Cedar, Oregon, creosoted — cost 70 

Cedar, Washington, creosoted — heaved 70 

Corduroy roads ... 66 

Cypress blocks 68 

Mesquite blocks 68 

Pine blocks — various, 70, 79 ; yellow 68, 79 

Plank roads. , -. 66 

Redwood blocks 68 

Tamarack blocks 68 

Australian hard woods 71 

Concrete base 72 

Cost 71 

Curbs ; details ; expansion joints 72 

Life 74 

Sanding 71 

Crown 30, 32 

Grades 28 

Joints, grooved , 29 

Noiseless 74-79 

YoNKBRS, N. Y. — bituminous macadam , 135 



195 



^\}\, 



2a 



JUL 36 1902 



ICOPYHEI TO CAT mv. 
JUL. 28 1902 



HiL. 31 1902 



